Copper

Copper (pronounced kop-er)

(1) A malleable, ductile, metallic element having a characteristic reddish-brown color, occurring as the free metal, copper glance, and copper pyrites: used as an electrical and thermal conductor and in such alloys as brass and bronze.

(2) As a color, a metallic, reddish brown.

(3) A slang term for a coin (usually of a smaller denomination) composed of copper, bronze etc.

(4) A slang term for a hedge (archaic).

(5) A slang term for a police or other law-enforcement officer, now usually as the shortened “cop”.

(6) In lepidopterology, any of several butterflies of the family Lycaenidae, as Lycaena hypophleas (American copper), having copper-colored wings spotted and edged with black.

(7) In slang and informal use, a tool or any of the various specialized items made from copper, where the use of copper is either traditional or vital to the function of the item.

(8) In historic UK & Commonwealth use, a large kettle (now usually made of cast iron), used for cooking or to boil the laundry (archaic and functionally extinct); a once popular term for any container made of copper.

(9) To cover, coat, or sheathe with copper.

Pre 1000: From the Middle English coper & copper, from the Old English coper & copor, from the Late Latin cuprum (copper), from the Latin aes Cyprium (literally “Cyprian brass” (ie metal from the island of Cyprus)), from the Ancient Greek Κύπρος (Kúpros) (Cyprus).  It was cognate with the Dutch koper (copper), the Old Norse koparr (copper), the German Kupfer (copper) and the Icelandic kopar (copper).  The alternative spelling coper (a hangover from the Middle English) is obsolete.  Copper & are nouns, verbs & adjectives, copperas is a noun, coppered & coppering are verbs & adjectives and coppery, cupric, cupreous & cuprous are adjectives; the noun plural is coppers.

In the Ancient Greek there was khalkos (ore, copper, bronze), a direct borrowing of the primitive Indo-European word meaning "ore, copper, bronze" and familiar in the Sanskrit ayah and the Latin aes.  In Classical Latin aes originally was used of copper but as technology evolved, this was extended to bronze (its alloy with tin) and because bronze was used much more than pure copper, the word's primary sense shifted to the alloy and a new word evolved for "copper," from the Latin form of the name of the island of Cyprus, where the copper mines were located.  Cyprus being the birthplace of Aphrodite (Venus), this led (in the way mythology adapted to the times) to the association of by alchemists of Aphrodite with copper.  Aes passed into the proto-Germanic where originally no linguistic distinction existed between copper from its alloys while in English it became “ore”.  In Latin vernacular, aes was used also to mean “cash, coin, debt, wages” in many figurative expressions. The chemical symbol Cu is from cuprum, from the Ancient Greek Κύπρος (Kúpros) (Cyprus).

The use to describe coins made of (or appearing to be made of) copper dates from the 1580s while to refer to vessels (jars, tubs, pots etc) made from the metal it came into use in the 1660s, the adjective cupreous (consisting of or containing copper (from the Late Latin cupreus (of copper), from cuprum (an, alternative form of cyprum (copper)) emerging in parallel.   The adjectival use in the sense of “made from or resembling copper” emerged in the 1570, a development from the verb, in use since the 1520s.  The alloy copper-nickel was first used to mint coins in 1728.  The trade of coppersmithing, practiced by the coppersmith (artisan who works in copper), was a creation of the early fourteenth century and was, as was practice at the time, soon used as a surname.  The noun copperplate (also copper-plate) described a "plate of polished copper, engraved and etched" dates from the 1660s and was later used figuratively to describe designs (wallpaper, woodcuts, carvings, carpet etc) with some resemblance to the styled metal.  Perhaps surprisingly, the adjectival sense in the sense of an allusion to the reddish-brown color isn’t documented until the turn of the nineteenth century (“cupric” used thus in 1799 and "copper-colored" after 1804) although it may earlier have been part of one or more oral traditions.

Symbol: Cu.
Atomic number: 29.
Atomic weight: 63.546.
Valency: 1 or 2.
Relative density: 8.96.
Specific gravity: 8.92 at 20°C.
Melting point: 1084.87±+0.2°C.
Boiling point: 2563°C

In an example of the way English must seem strange to speakers of more apparently logically languages, the use of “cop” as a slang term for “police or other law-enforcement officer” is a shortening of “copper” but that is etymologically unrelated to the metal, the use of “copper” to describe policemen (at a time all were men” derived from the English “cop”.  The construct was cop (to take, capture, seize) +‎ -er (the agent suffix).  Cop is of uncertain origin but the most likely link is with the Middle English coppen & copen, from the Old English copian (to plunder; pillage; steal) although some etymologists have also suggested the Middle French caper (to capture), from the Latin capiō (to seize, grasp) or the Dutch kapen (to seize, hijack), from the Old Frisian kāpia (to buy), source of the Saterland Frisian koopje and the North Frisian koope.  A perhaps related form was the Middle English copen (to buy), from the Middle Dutch copen.

New York's Statute of Liberty with the copper skin colored as it would have appeared in France, prior to being shipped to the US for erection in  in 1886 (left) and as it appeared decades later, the metal showing the effects of oxidization (right).  

The expression “to cop” was thus used in the sense of “to steal” but also (as a transitive verb) “to (be forced to) take; to receive; to shoulder; to bear, especially blame or punishment for a particular instance of wrongdoing”, hence the expressed notions of “cop the blame”, “cop an injury” etc.  It was the association with crime and violence which in the nineteenth century saw "copper" (one who cops (apprehends) the criminal) adopted in the UK (first documented in 1846) to describe what were then the still relatively novel (in the sense of a structured, publicly-funded force) policemen and as “cop”, the world spread world-wide.  Cop also had a mono-syllabic appeal to many sub-cultures who took up the sense of “to obtain; acquire; purchase”; it was used (1) by drug users to express acquisition of narcotics, (2) among anoraks (train-spotters, plane-spotters, bird-watchers etc) to mark the observation and recording of something unique or at least rare and (3) by those living off immoral earnings (pimps), to speak of the recruitment of a prostitute to the lineup.  There was also the alleged slang form “fair cop”, said to be used by criminals (to cops) when admitting guilt although whether this was as common in real life as it was in the imaginations of crime writers isn’t known although “bent copper” (a corrupt police officer) still enjoys some currency.

JTC Roofing in the UK provided a chart using the Statute of Liberty to illustrate the natural process by which copper gradually changes in color from the original reddish-brown to green, a chemical reaction between the metal and the oxygen in the atmosphere, something known as oxidation.  In an aesthetic sense, the transition to green is part of copper’s charming patina but it’s also functional, providing a protective coating which protects surface deterioration and in this it differs from a ferrous metal like iron which, under oxidation, becomes rusted, the rust eating into the material.  The result can be seen in the light bluish-green copper facades which adorn many copper rooftops and structures and the pallette evolves over years before the familiar green tint achieves a final hue, something influenced also by atmospheric and climatic conditions.

The patination of copper induced by oxidation can be emulated in hair colors: Lindsay Lohan demonstrates. 

Helpfully, World of Chemicals has explained the chemistry.  When in 1886 the Statute of Liberty was assembled and erected after being shipped from France, it was a quite dull brown, reflecting the process of oxidation which had already taken from the metal the shininess which the coppersmiths and engineers would have seen when first working on the pates in Paris and it would take another 30-odd years of weathering before the now familiar color settled.  This patination is fine if a structure for decades remains untouched but in some uses in architecture (especially roofs which are vulnerable to damage), it’s sometimes necessary to replace copper panels which can result in an unsightly patchwork of colors.  For this reason, the industry has developed processes of pre-patination which can render copper panels with specific degrees of patination to match a sample of the damaged item, thus providing a close color-match.

Because of its location and the era in which it has stood, the particular path to verdigris (from the French vert-de-gris (literally “green of Greece”)) assumed by the Statute of Liberty was influenced by the unique environmental conditions.  Although the process is linguistically encapsulated as “oxidation”, it's not a simple single reaction between copper and oxygen because the generated green oxide continues to react to make copper carbonates, copper sulphide, and copper sulphate.  Initially, the copper reacts with oxygen from the air in a redox reaction, the metal donating electrons to oxygen, which oxidises the copper and reduces the oxygen, the copper oxide continuing to react with oxygen to form copper oxide.  However, for many of the decades in which the statute stood, the atmosphere contained much sulphur from the burning of coal and this induced another reaction which produced copper sulphide (black) which reacts with atmospheric carbon dioxide and hydroxide ions from water vapour, forming three compounds all of which exist in shades of blue or green.  The speed at which the patina develops and evolution of the colour depends on factors like temperature, humidity and air pollution, not just the presence of oxygen and carbon dioxide and, in another time, in another place, things would have unfolded differently.

Statue of Liberty (1962), silkscreen print by Andy Warhol. 

Andy Warhol (1928-1987) produced a few depictions of the Statute of Liberty, mostly variations of the familiar theme made famous by his prints of Marilyn Monroe (1926–1962) but one with a touch of something original was a silkscreen rendering in 1962 of multiple tiled images in 3D.  At auction by Christies (New York) in 2012, it sold for US$43.8 million, part of a collection of contemporary art that realized an encouraging US$412.3 million, regarded at the time as a sign the market was recovering from the shock of the global financial crisis (GFC); the US Federal Reserve (The Fed) must have been pleased to see all that quantitative easing being spent wisely.  Even so, it didn’t set a record for a Warhol, Eight Elvises sold in a private sale 2008 for a reputed US$100 million although the auction house did throw in a pair of 3D glasses with the catalogue so there was that.  In 2013, another Warhol from 1963 set a pop-art record which stands today, Silver Car Crash (Double Disaster) selling at auction for US$105.4 million.

Malachite

Malachite (pronounced mal-uh-kahyt)

(1) In mineralogy, a bright-green monoclinic mineral, occurring as a mass of crystals (an aggregate).  It manifests typically with a smooth or botryoidal (grape-shaped) surface and, after cutting & polishing, is used in ornamental articles and jewelry.  It’s often concentrically banded in different shades of green, the contrast meaning that sometimes lends the substance the appearance of being a variegated green & black.  Malachite is found usually in veins in proximity to the mineral azurite in copper deposits.  The composition is hydrated copper carbonate; the chemical formula is Cu₂CO₃(OH)₂ and the crystal structure is monoclinic.

(2) A ceramic ware made in imitation of this (in jewelry use, “malachite” is used often as a modifier).

(3) In mineralogy, as pseudomalachite, a mineral containing copper, hydrogen, oxygen, and phosphorus.

(4) In mineralogy, as azurite-malachite, a naturally-occurring mixture of azurite and malachite

(5) In organic chemistry, as malachite green, a toxic chemical used as a dye, as a treatment for infections in fish (when diluted) and as a bacteriological stain.

(6) Of a colour spectrum, ranging from olive-taupe to a mild to deeply-rich (at times tending to the translucent) green, resembling instances in the range in which the mineral is found.  In commercial use, the interpretation is sometimes loose and some hues are also listed as “malachite green”).

1350-1400: From the Middle French malachite, from the Old French, from the Latin molochītēs, from the Ancient Greek malachitis (lithos) (mallow (stone)) & molochîtis (derivative of molóchē, a variant of maláchē), from μολόχη (molókhē) (mallow; leaf of the mallow plant).  It replaced the Middle English melochites, from the Middle French melochite, from the Latin molochītis.  Malachite is a noun & adjective; the noun plural is malachites.

A pair of Malachite & Onyx inlay cufflinks in 925 Sterling Silver (ie 92.5% pure silver & 7.5% other metals), Mexico, circa 1970.

Although in wide use as a gemstone, technically malachite is copper ore and thus a “secondary mineral” of copper, the stone forming when copper minerals interact with different chemicals (carbonated water, limestone et al.  For this reason, geologists engaged in mineral exploration use malachite as a “marker” (a guide to the likelihood of the nearby presence of copper deposits in commercial quantities).  It’s rare for malachite to develop in isolation and it’s often found in aggregate with azurite, a mineral of similar composition & properties.  Visually, malachite & azurite are similar in their patterning and distinguished by color; azurite a deep blue, malachite a deep green.  Because the slight chemical difference between the two makes azurite less stable, malachite does sometimes replace it, resulting in a “pseudomorph”.  Although there is a range, unlike some minerals, malachite is always green and the lustrous, smooth surface with the varied patterning when cut & polished has for millennia made it a popular platform for carving, the products including al work, jewelry and decorative pieces.  For sculptors, the properties of malachite make it an easy and compliant material with which to work and it’s valued by jewelers for its color-retention properties, the stone (like many gemstones) unaffected by even prolonged exposure to harsh sunlight.  Despite the modern association of green with the emerald, the relationship between mankind & malachite is much more ancient. evidence of malachite mining dating from as early as 4000 BC found near the Isthmus of Suez and the Sinai whereas there’s nothing to suggest the emerald would be discovered until Biblical times, some two millennia later.

Lindsay Lohan in malachite green, this piece including both the darker and lighter ends of the spectrum.

The Malachite is relatively soft meant it was easy to grind into a powder even with pre-modern equipment; it was thus used to create what is thought to be the world’s oldest green pigment (described often as chrysocolla or copper green).  In Antiquity, the dye was so adaptable it was used in paint, for clothing and Egyptians (men & women) even found it was the ideal eye makeup.  Use persisted until oil-based preparations became available in quantity and these were much cheaper because of the labor-intensive grinding processes and the increasing price of malachite which was in greater demand for other purposes.  This had the side-effect of creating a secondary market for malachite jewelry and other small trinkets because the fragments and wastage from the carving industry (once absorbed by the grinders for the dye market) became available.  The use in makeup wasn’t without danger because, as a copper derivate, raw malachite is toxic; like many minerals, the human body needs a small amount of copper to survive but in high doses it is a poison’ in sufficient quantities, it can be fatal.  Among miners and process workers working with the ore, long-term exposure did cause severe adverse effects (from copper poisoning) so it shouldn’t be ingested or the dust inhaled.  Once polished, the material is harmless but toxicology specialists do caution it remains dangerous if ingested and any liquid with which it comes in contact should not be drunk.  Despite the dangers, the mineral has long been associated with protective properties, a belief not restricted to Antiquity or the medieval period; because the Enlightenment seems to have passed by New Agers and others, malachite pendants and other body-worn forms are still advertised with a variety of improbable claims of efficacy.

The Malachite Room of the Winter Palace, St Petersburg, Russia was, during the winter of 1838-1839, designed as a formal reception room (a sort of salon) for the Tsar & Tsarina by the artist Alexander Briullov (1798–1877), replacing the unfortunate Jasper Room, destroyed in the fire of 1837.  It’s not the only use of the stone in the palace but it’s in the Malachite Room where a “green theme” is displayed most dramatically, the columns and fireplace now Instagram favorites, as is the large large urn, all sharing space with furniture from the workshops of Peter Gambs (1802-1871), those pieces having been rescued from the 1837 fire.  Between June-October 1971 it was in the Malachite Room that the Provisional Government conducted its business until the representatives were arrested by Bolsheviks while at dinner in the adjoining dining room.  The putsch was denounced by the Mensheviks who the Bolsheviks finally would suppress in 1921.

Polished malachite pieces from the Congo, offered on the Fossilera website.

Where there is demand for something real, a supply of a imitation version will usually emerge and the modern convention is for items erroneously claiming to be the real thing are tagged “fake malachite” while those advertised only as emulation are called “faux malachite”.  Although not infallible, the test is that most fake malachite stones are lighter than the real thing because, despite being graded as “relatively soft” by sculptors, the stone is of high in density and deceptively heavy.  The patterning of natural malachite is infinitely varied while the synthetic product tends to some repetition and is usually somewhat brighter.  The density of malachite also lends the stone particular thermal properties; it’s inherently cold to the touch, something which endures even when a heat source is applied.  Fake malachite usually is manufactured using glass or an acrylic, both of which more rapidly absorb heat from the hand.

Lindsay Lohan with Rolex Datejust in stainless steel with silver face (left) and the Rolex's discontinued "malachite face" (centre & right).  Well known for its blue watch faces, during the more exuberant years of the 1970s & 1980s the company “splashed out” a bit and offered a malachite face.  The Datejust is now available with a choice of nine faces but the Green one is now a more restrained hue the company calls “mint green”.

Trinitite

Trinitite (pronounced trin-a-tight)

(1) The glassy residue left on the desert floor after the Trinity nuclear bomb test of 16 July 1945 at Alamogordo, New Mexico, USA.

(2) By extension, any melt glasses left by nuclear bombs (known also as Alamogordo, atomsite glass or nuclear melt glass).

1945: Compound word trinit(y) +‎ -ite.  Trinity is from the Middle English trinitie & trinite from the Anglo-Norman trinitie or trinite (or ternite, trenite, trinetei, trinitiet & trinitet) from the Latin trīnitātem, accusative singular of trīnitās (the number three; a triad; the Trinity), from trīni (from trīnus (triple) from trēs, from the Proto-Italic trēs, from the primitive Indo-European tréyes (three)) + the suffix -itās from the Proto-Italic -itāts & -otāts from the primitive Indo-European –tehts, the suffix forming nouns indicating a state of being.  The suffix –ite is from the Ancient Greek -ίτης (-ítēs) and was adopted in Latin as part of Greek loanwords, both as –ītēs but also often as -īta.  It was used in Biblical tribal names (Thus either Levītēs or Levīta; plural in –ītae) and in the Medieval Latin of religious groups, such as Marcionītae, Ebiōnītae, Monophysītae.  It’s an adjective-forming suffix, especially of nominalised adjectives identifying groups of people as "those belonging to".  Trinitite is a noun; the noun plural is trinitites.  The verb trinitize is unrelated; it's from Christian theology and means "to divide into a trinity".

It was the physicist Robert Oppenheimer (1904–1967), head of the Manhattan Project which developed the first atomic weapons, who choose the name of the test site for the first atom bomb: Trinity.  He’s remembered for a snatch of verse he said the sight of the first atomic explosion made him recall, words from the Bhagavad Gita: Now I am become Death, the destroyer of worlds.  Oppenheimer also had a fondness for the metaphysical poetry of John Donne (1572–1631), the Church of England cleric, and said he remembered also:

As West and East
In all flat Maps—and I am one—are one
So death doth touch the Resurrection

While those lines do not a Trinity make, others do such as Batter my heart, three person’d God and the Holy Trinity permeates much of his Donne's work.

Variations since Trinity include kharitonchik (melt glasses from the Soviet nuclear bomb Semipalatinsk Test Site in Kazakhstan), impactite (metamorphic minerals caused by meteor heating of non-meteoritic materials), impact glass (melt glasses caused by meteor heating of non-meteoritic materials), fulgurite (melt glasses caused by lightning strikes) and fusion crust (metamorphic minerals on the surface of meteorites caused by atmospheric entry heating).  Trinitite has also been referred to as atomsite or Alamogordo glass (after the nearby city).

Physicist Norris Bradbury (1909–1997; director of the Los Alamos National Laboratory 1945-1970), group leader for bomb assembly, stands next to the partially assembled "Gadget" (code-name for the first plutonium A-bomb) atop the test tower, New Mexico, 16 July 1945).

The Trinity test of the plutonium A-bomb in New Mexico in July 1945 was a genuine test.  The uranium A-bomb which had also been built and which ultimately was dropped on Hiroshima in August was a device in which the scientists had such faith that it was deemed no test was necessary, something that sounds astonishing now but among all the physicists and engineers attached to the Manhattan Project (the A-bomb development team), there were no dissenting voices.  As a uranium bomb, the Hiroshima device was (at least for decades) a genuine one-off, all subsequent nuclear weapons being plutonium-based devices (and that may still be true; the details of the DPRK’s (North Korea) bombs remaining murky).  A uranium bomb turned out to be (relatively) easy to design and build and the trigger mechanism was simple but production of uranium to the specification required was a slow and exacting process given the machinery at the time available.  By contrast, a supply of weapons-grade plutonium was possible with the existing facilities but it was a formidable engineering challenge to create the trigger mechanism while ensuring the device remained within the size and weight parameters of a gravity bomb dropped from an aircraft which would have to fly thousands of miles to reach the target.  The Hiroshima bomb could be made to explode simply by firing a uranium bullet into the uranium core but if that approach was used with plutonium, all that would happen would be the melting of the core.  The solution was to surround the core with sufficient high-explosive to create the pressure required to trigger the chain reaction.  It was this process that the Trinity was staged to test.

Trinitite on the desert floor.

Although the test was over seventy-five years ago and completely fulfilled the purpose of testing the plutonium bomb, it was in another sense an extraordinary experiment in high-energy physics and even in the twenty-first century, analysis of the data and the physical aftermath at the site continues to reveal interesting discoveries.  Geological excavations in 2005 confirmed that the explosion, as predicted, initially pushed-down the ground but that it then rebounded, forcing the material upwards into the fireball in the sky where it was vaporized before cooling and crystallizing, eventually raining down in the form of the trinitite fragments.  Most of the trinitite was green because of the iron content in the sand while a smaller volume was black because their source was the iron from which Trinity’s tower structure was constructed and, being refined and processed, the iron content was much greater than that in the sand.  Finally, among all the trinitite, there was found a tiny number of red crystals which gained their color from all the copper cables which were also vaporized.  The propensity of copper to color its immediate environment was well-known, the mining conglomerate Rio Tinto formed in 1873 with a company name from the Rio Tinto (red river or Tinto River); the highly acidic river in the Sierra Morena mountains of southwestern Spain that runs red & orange because of the high copper content in the surrounding soil.

Red Trinitite.

Beginning in that fraction of a second when the nuclear age was born was the process which produced the red crystals, the extreme pressure and temperature (the Trinity site was briefly hotter than the surface of the Sun) forging a most unusual structure within one grain of the material just 10 micrometers across (barely longer than a red blood cell).  Made from silicon, copper, calcium and iron, the rare form of matter was called a quasicrystal.  Normally, crystals are made from atoms locked in a lattice that repeats in a regular pattern but quasicrystals, while having a structure that is orderly like a normal crystal, don’t have patterns which repeat and this grants quasicrystals properties forbidden to normal crystals.  First discovered in laboratory observations during the 1980s, quasicrystals also occur naturally in meteorites, matter transformed by stars, another place of extreme heat and pressure.

The Trinity test, the world's first nuclear explosion.

Until their observation in the 1980s, physicists regarded quasicrystals as “impossible” because they would have violated the rules scientists had over centuries constructed to define crystalline materials; the quasicrystal was thus a ‘black swan” moment in physics.  Traditionally, crystals were held to possess what were known as “rotational symmetries”, places where the structure could symmetrically be split in half, along one, two, three, four and six axes.  The black swan quasicrystal broke the rules or, more precisely, proved the rules were wrong, demonstrating instead an “icosahedral symmetry” a construct which includes six independent five-fold symmetry axes; as solids with these rotational symmetries, the quasicrystal is unique.  To the US military-industrial complex, it may also prove uniquely useful because, if a sample could be obtained of a quasicrystal created during nuclear tests conducted by other nations, it could be analyzed and might yield new understandings of their programs and weapons.  It’s always been possible to examine radioactive debris and gases to build models of how the devices were built and the materials used but those signatures decay.  Not only might a quasicrystal reveal new information but, and this is obviously most useful if the analytical process uses non-destructive tests, quasicrystals are a form of matter which goes as close (theoretically) to lasting forever as any yet known.

Lindsay Lohan (right) illustrating the typical hue of green trinitite (left).

What’s sometimes described as “trinitite green” and used for glass crockery or decorative items is misleading because such purity was never in New Mexico after the blast.  A glassy material, most trinitite exists in a range between a pale to olive green but smaller quantities in red and black have also been observed, the coloration dependent on the specific minerals and materials in the blast site.  The green is a product of iron while the red comes from the copper electrical wiring used in the Trinity test equipment being fused together with the quartz and feldspar sand grains from the desert floor.  A quirk is that red trinitite is brightly fluorescent under short wave ultra-violet light whereas the more abundant green variety of typically shows little to no fluorescence under UV, the difference again due to the mineral composition.  Black trinitite is rarest, formed by virtue of the presence of iron alone from the tower with no copper content.

Cloisonné

Cloisonné (pronounced kloi-zuh-ney or klwa-zaw-ney (French))

(1) A decorative technique for metalwork, especially brass, whereby colored enamel is baked between raised ridges of the metal; among those for whom "price-taggery" is the measure of things, it was sometimes disparaged as a cheaper alternative to jeweled encrustation or filigree.

(2) Pertaining to, forming, or resembling cloisonné or the pattern of cloisonné.

(3) As applied to metalwork, objects decorated by this technique collectively.

1863: From the French cloisonné (divided into compartments, partitioned (especially in reference to surface decoration)), from the twelfth century Old French cloison (partition), from cloisonner (enclosure; to divide into compartments) from the Provençal clausiō, from the Vulgar Latin clausiōn, stem of clausiō (closed), noun of action from past participle stem of claudere (to close; shut).  The alternative spelling cloisonne is now more common in English.  Cloisonné is a noun; the noun plural is cloisonnés.  The noun cloisonnism describes a school of postimpressionist painting and the verb cloisonner (to partition, to compartmentalize) is French.

Lindsay Lohan wearing vintage art deco bracelet in triangulated black & white, May 2007.

There were several steps in the cloisonné enamel process and they have been little changed since the process was first used in Egypt prior to 1800 BC when gold ornaments were inlaid with small pieces of turquoise, lapis lazuli, carnelian and garnet, the inlays held in position by ribs soldered to the gold base.  Although there’s no surviving evidence in archaeological digs, the speculation of Egyptologists is that goldsmiths and glass workers collaborated to forge or fabricate their creations using artificial gems.  Pieces of colored glass were substituted for the stones and some appear to have been cemented in place.  The modern sequence is usually:

(1) Design and Preparation: The artisan will create a two dimensional sketch which develops into a detailed design; this can be on paper or a digital rendering which is then transferred onto a metal object, made usually of bronze, copper or gold.

(2) Wire Application (Cloisons): Thin metal wires (usually of copper or gold) are shaped to suit the design; these are soldered or glued to the metal surface, forming compartments (cloisons).  It’s these wires which lend a three dimensional form to the design, acting as the barriers which will contain the various enamel colors.

(3) Enamel Filling: Enamel (powdered glass which is mixed with water to form a paste) is applied within the cloison compartments.  While there are designs which used only the one shade of enamel, historically the style is associated with contrasting colors, some vivid, some dark.

(4) Firing: Once the compartments have been filled, the object is fired in a high-temperature kiln.  This causes the enamel to melt, fusing it with the metal; depending on the design, multiple firings may be required to build up the enamel layers and achieve the desired thickness and finish.

(5) Polishing: After the final firing, the surface of the object is polished, this both smoothing the enamel to its final shape and enhancing the color.  As part of this process, some enamel may be removed so the metal wires are granted greater prominence better to define the shapes.

French Second Empire gilt cloisonné enamel carriage clock, circa 1870.

The intricate metalwork and detailed cloisonné engravings associated with the clocks of the First French Empire have always attracted collectors and there’s a view in the industry they’re superior in just about every way to those of the Second Empire.  They certainly tend to be more expensive.  There are those who prefer the later clocks, especially the more restrained.  For the discerning, a sub-genre of Second Empire horology was the carriage (or travelling) clock, small, sturdy and created in shapes suitable to packing in regular-sized boxes.  The earliest were purely functional with little embellishment but their diminutive form appealed to designers seeking to create exquisite miniatures.  From the mid-century on, an increasing number were produced for household use and it’s doubtful many were much used by those on the move.

1967 Ferrari 275 GTB/4 NART Spider.

The cloisonné "N.A.R.T." badge.

The Ferrari 275 GTB/4 NART Spider was a roadster commissioned by Ferrari's North American concessionaire, Italian-born Luigi Chinetti (1901–1994) who ran the North American Racing Team (N.A.R.T.) and wanted to offer something in the spirit of the charismatic 250 California Spiders (1957-1963).  Built by Ferrari's coachbuilder Scaglietti, the NART Spider was certainly a worthy successor but, being very much a traditional sports car with few of the luxury fittings to which buyers had quickly become accustomed, demand was subdued, most preferring its less raucous companion, the 330 GTS which pampered occupants with niceties like power steering, electric windows and air conditioning.  The NART's high price didn't help and of the planned run of 25, only ten were built.  Thus mostly unwanted when new, as a used car the performance of the 275 NART has been stellar, chassis #10709 selling at auction in 2013 for US$27.5 million.  Informally always known as the "NART Spider" despite the factory not using the designation, the only hint of its unusual gestation was a cloisonné badge with the N.A.R.T.'s logo, installed on the Kamm tail.

1967 Ferrari 275 GTB/4 NART Spider.

The NART's existence also created a footnote in the history of Ferrari nomenclature.  Although the ten have always been regarded as official factory models, Enzo Ferrari (1898-1988) was noticeably restrained in his enthusiasm for the venture and instead of being named 275 GTS/4 as would have been the current practice, it was listed in the records of both Scaglietti and the factory as the 275 GTB/4 NART spider.  That may have been because there had already been a 275 GTS (1964-1966) although it had been replaced by the 330 GTS by the time the NART cars were built or it may simply have been Il Commendatore didn't like his plans being changed.  Because of the high prices the things attract when from time to time they are offered at auction, the sales are always well publicized and the modern practice seems to be to label them as 275 GTB/4S, 275 GTB/4s or 275 GTB/4*S.  Given the well-known status of the NART machines the appended "S" seems superfluous.

Rubicon

Rubicon (pronounced roo-be-kon)

(1) A river, some 50 miles (80 km) in length in northern Italy, flowing eastwards into the Adriatic.

(2) A point of no return expressed as crossing the Rubicon (sometimes not capitalized; both considered correct).

(3) A penalty in piquet by which the score of a player who fails to reach 100 points in six hands is added to his opponent's total.

The Latin rubicō was derived from the adjective rubeus (red).  The river's name was from rubicundus (ruddy) and was a reference to the color of the soil on its banks.  Two-thousand odd years later, the mining company Rio Tinto similarly picked up its name from the river where copper was first mined.  Rio Tinto in Spanish translates as "colored river", the color caused by copper deposits leeching into the waters.  The figurative phrase "cross (occasionally "pass") the Rubicon" meaning "take a decisive step" or "past the point of no return" is from the 1620s, a reference to the crossing in 49 BC, in defiance of Roman law, when Julius Caesar (100-44 BC; Roman general and dictator of Rome 49-44 BC) left his province to attack Pompey.

The die it is cast

A kind of Mason-Dixon Line from Antiquity, during the Roman republic, the Rubicon marked the boundary between the Roman province of Cisalpine Gaul and Italy proper, controlled directly by Rome to the south.  Governors of Roman provinces were granted an essentially absolute executive authority in their territory, the governor serving as general of the Roman army within his province.  Roman civil law specified that only elected consuls and praetors could hold such authority within Italy so any provincial governor entering Italy at the head of his troops forfeited his office was therefore no longer legally allowed to command troops.  It was more than an administrative point because exercising military authority without authority was a capital offense and this extended to the soldiers under command.  The point of the law was to prevent generals with political ambitions from marching on Rome with their own army.

2015 Jeep Wrangler Rubicon.

In 49 BC, Julius Caesar led a single legion over the Rubicon from Cisalpine Gaul to Italy to make his way to Rome; in doing this, he deliberately broke the law and made war inevitable.   Writers at the time noted Caesar paused on the northern bank and waited a while, attributing this delay to his contemplation of the enormity of what he was about to do; a general needs to think a bit before committing mutiny.  As described by Suetonius Tranquillus (circa 69–circa 128), as he crossed the Rubicon, Caesar uttered the famous phrase ālea iacta est (the die has been cast).  The phrase crossing the Rubicon has endured to refer to individuals or groups committing irrevocably to a risky or revolutionary course of action.  It means the point of no return, what’s done is done and can’t be undone.

Julius Caesar and the Crossing of the Rubicon (1493-1494) by Francesco Granacci (1469-1543).

An insight into the tastes of those who actually paid for art during the Renaissance, the imagery presented in Granacci's work would have been far removed from how Caesar, a practical military man at the head of a legion, would have done a river crossing into hostile territory.  The painting does though reflect the influences from the art of Antiquity, especially in the representation of armors.  Granacci  trained in Florence, with Michelangelo (1475–1564), in the workshop of Domenico Ghirlandaio (circa 1448-1494), and the two then studied sculpture in the Medici garden at the Casino Mediceo di San Marco under the supervision of Bertoldo di Giovanni (circa 1420-1491).  One of the noted artists of the era and a long-time collaborator of Michelangelo, his best remembered work is probably the high altarpiece for the church of Sant'Apollonia, Florence (1530).

BeiBao Lindsay Lohan spare wheel cover on Jeep Wrangler Rubicon.

Caesar's swift military action forced the lawful consuls and a large part of the Roman Senate to flee Rome in fear, his subsequent victory in the civil war and takeover of the state ensuring punishment for the infraction would never be imposed.

Drahtfunk

Drahtfunk (pronounced draat-fuenk)

The broadcasting of audio signals through wire or cable connections rather than airwaves.  Drahtfunk translates from the German as “wired radio”, the collective noun being Drahtfunkeinrichtungen (wired radio equipment).

1937: A German compound noun, the construct being draht (wired) + funk (radio).  The German Funk can also be translated as "wireless" so Drahtfunk can be understood as "wired wireless" so that's good.   Draht was from the Middle High German drāt (wire, thread), from the Old High German drāt or thrāt, from the Proto-Germanic þrēduz, from the primitive Indo-European treh- from terh- (rub, twist).  It was related to drehen (to turn, twist), with which it was still associated in early modern German (evidence for which is the insertion of the lengthening -h-, used only before sonorants or stem-finally).  It was cognate with the Dutch draad, the Low German Draat, the English thread, the Danish, Norwegian & Swedish trad and the Icelandic þráður.  The genitive is Drahtes, the plural Drähte and the diminutive, Drähtchen.  In Modern German, the sense of wire (thread of metal; conductor) remains but is obsolete for threads made from other materials.  Funk was from the Proto-Germanic funkô or fankô (spark), from the primitive Indo-European speng- or spheng- (to shine).  It was cognate with the Middle Low German funke & fanke (spark), the Middle Dutch vonke (spark), the Old High German funcho & funko (spark) and the German Funke (spark).  In the Middle English it existed as funke & fonke (spark) from the Old English funca & fanca (spark), from the same roots as the Germanic although some other meanings in English evolved independently.

Funk, stemming from funken (spark), came to mean “radio” in German, because some of the earliest wireless telegraphs used spark gap transmitters, thus creating the association with radio, and many compounds have been formed, added both at beginning (Funkspruch, Funkbearbeitung) and end (Mobilfunk, Bordfunk).  Drahtfunk is a masculine noun; in German, both the spelling of the word and the article preceding the word can change depending on whether it is in the nominative, accusative, genitive, or dative case.  Given the meaning, it exists as a masculine singular only; no plural form.  The nominative is der Drahtfunk, the accusative den Drahtfunk, the genitive des Drahtfunks and the dative dem Drahtfunk.

Radio technology under the Third Reich

Developed during the 1930s in Germany, wired radio was analogous with the technological dualism of ADSL (asymmetric digital subscriber line), the DSL technology which, beginning in 1998, was the first convenient and widely adopted domestic internet broadband.  Like ADSL, Drahtfunk ran (at a higher frequency than telephony) over the analogue copper pairs used for fixed line telephones, the attraction for both systems being the copper wires were usually existing infrastructure, thus making it faster and cheaper to deploy the new technology.  The mechanism of the physical connection would also be familiar to anyone who used an ADSL service: a crossover with two outputs (often called the "splitter box) connected to the telephone socket, one (input/output) feed connected to the handset, the (input only) to the radio's antenna socket.  Although Drahtfunk was first implemented at scale during the Third Reich (1933-1945), it was actually developed by the postal service (responsible for telephony) during the Weimar Republic (1918-1933).  Had it earlier been available there's little doubt the Nazis would have sought to use the medium because they understood the power of voice, part of their campaign material in the (many) elections they contested under the republic including gramophone records containing edited highlights of Adolf Hitler's (1889-1945; Führer (leader) and German head of government 1933-1945 & head of state 1934-1945) speeches.  Because the technology of the time permitted at most around 15 minutes per side of a disk, some editing was required.  Whether the authorities would have permitted the Nazis to broadcast in this way isn't known and the low take-up rate of phone-lines into homes would anyway have limited the value.         

Although, most curiously, there's little to suggest they ever explored the possibility of television, the  Nazis were enthusiastic about radio as a medium for political indoctrination, Dr Joseph Goebbels (1897-1975; Nazi propaganda minister 1933-1945), who, while evil, was a fair judge of such things, thought the success of the régime “…would have been impossible” without radio.  However, in the early 1930s, receiver sets were expensive, even when subsidized by the state so Drahtfunk was developed in the hope sets could cheaply be mass-produced and use the existing phone lines.  However, advances in electronics made conventional radios cheaper and the take up of telephone connections was slower than expected so Drahtfunk was barely used by households, adopted mostly by the military which had run literally thousands of kilometers of telephone wires to ensure a independent means of communications between bases and to headquarters staff, the other attraction being that unlike any implementation of RF (radio frequency) transmission which pass through the air, wired messaging was inherently secret.

Pamphlet issued by the Allied Control Commission explaining the operation of Drahtfunk, Berlin, January 1946.

It was revived in 1943 when it was realized allied bomber fleets were using radio transmissions to hone in on targets, something especially significant at night when urban areas were subject to blackouts, thus depriving aircrew of visual navigation and bomb-aiming.  As a counter-measure, conventional radio signals were switched off when enemy aircraft were approaching, listeners advised to switch to the Drahtfunk by plugging their set into a splitter-box wired to the telephone cable, the process the same as an ADSL connection which plugs the two lines into a line-splitter or filter.  In the post-war years, US occupation forces continued to use the system in their Berlin occupation zone after being unable to reach agreement with the Russians to share the conventional broadcast system, all the infrastructure physically in the Soviet zone.  Thus, after it was estimated the installation of medium and long wave transmitters in the American sector would take months, beginning in December 1945, Drahtfunk services were resumed under the name DIAS (wire radio in the American sector (later renamed RIAS)).  Other German radio programming was available through the system in other parts of the country including the BFN (British Forces Network) program and it wasn't until 1963 the use in most of the FRG (the Federal Republic of Germany, the old West Germany) was discontinued, the service maintained in West Berlin for a further three years.  Elsewhere in Europe, wired radio was adopted because because it was simple, reliable and delivered fine reception unaffected by atmospheric conditions, Switzerland ceasing transmission only in the 1990s because of incompatibilities when ISDN (Integrated Services Digital Network) lines were introduced for telephony.  In Sweden, the system proved especially useful because of (1) the peculiarities in the behavior of radio waves at the more northern latitudes and (2) the demands in terms of physical broadcast infrastructure (towers & transmitters) required to service a narrow, elongated landmass.  Because of the high penetration of telephone lines in Sweden by the late 1940s, wired radio was able to provide a high-quality service to the sparsely populated north and it was extensively deployed until advances in technology in the 1960s rendered it unnecessary.