Cobalt

Cobalt (pronounced koh-bawlt)

(1) A brittle, hard, lustrous, silvery-white-gray element (a ferromagnetic metal) which is found principally in cobaltite and smaltite and is widely used in (1) the rendering of both heat-resistant and magnetic alloys, (2) in clinical oncology and (3) as a blue pigment used to color ceramics, glass and other materials.

(2) As cobalt blue, a deep blue pigment derived from cobalt; zaffre.

(3) As cobalt therapy (known colloquially as the “cobalt ray”), a gamma ray treatment first used in the early 1950s in clinical oncology executed with external beam radiotherapy (teletherapy) machines using the radioisotope cobalt-60 with a half-life of 5.3 years.

1675–1685: From the German Kobalt & Kobold (a variant of Koboldkobold), from the Middle High German kobolt (household goblin), the name derived from the belief held by silver miners in the Harz Mountains that malicious goblins placed it in the silver ore, based on the rocks laced with arsenic and sulfur which degraded the ore and caused illness.  The construct was the Middle High German kobe (hut, shed) + holt (goblin) from hold (gracious, friendly), a euphemistic word for a troublesome being, designed to avoid offending the creature and thus inviting retribution.  It thus became part of German folk culture as an earth-elemental or nature spirit.  Although much rarer, the metallic element closely resembles nickel and was documented by but much rarer) was extracted from this rock. It was mentioned in the alchemy notes of Paracelsus (the Swiss physician, alchemist, lay theologian, and philosopher of the German Renaissance Theophrastus von Hohenheim (circa 1493-1541)), but as an element its discovery is credited to the Swedish chemist and mineralogist Georg Brandt (1694–1768) who in 1733 gave it the name.  Although it has since the mid-sixteenth century been used as a coloring agent for glass and ceramics, “cobalt blue” didn’t come into formal use until 1835.  There is also cobalt green (A variety of green inorganic pigments obtained by doping a certain cobalt oxide into colorless host oxides.  Cobalt & cobaltite are nouns and cobaltic, colbaltous & colbaltesque are adjectives; the noun plural is cobalts.

Cobalt ore.

Chemical symbol: Co.
Atomic number: 27.
Atomic weight: 58.93320.
Valency: 2 or 3.
Relative density (specific gravity): 8.9.
Melting point: 1495°C (2723°F).
Boiling point: 2928°C (5302.4°F).

Currently, most of the world's cobalt is supplied by mines in the Democratic Republic of Congo (the DRC, the old Republic of Zaire (1971-1997)) which account for some 60% of annual production.  Because of (1) industry economics and (2) the natural geological occurrence of the minerals, cobalt typically is extracted as a by-product of copper or nickel mining operations.  Smaller-scale mining is also undertaken in Canada, Australia, Russia and the Philippines.

Bugatti Type 35 (1924-1930) in Bleu de France (Blue of France, at the time often called Bleu Racing Français (French Racing Blue)) (left) and Bugatti Veyron 16.4 Super Sport Vitesse (2012–2015) in bleu cobalt over Bleu de France (right).  The factory still offers a variety of blues including bleu cobalt.

In the early days of motorsport, cars were painted in accord with their country of origin (the corporate liveries reflecting the source of the sponsorship didn’t reach all categories until the late 1960s) and the French chose blue.  Originally it was the exact shade used on the tricolore (the national flag) but teams soon adopted various shades.  The British were allocated green which became famous as the dark shade used on the Bentleys which raced at Le Mans in the 1920s but it too was never exactly defined and over the decades lighter and darker hues were seen.  The Italians of course raced in the red best represented by Ferrari’s Rosso Corsa (Racing Red) although in the era red at least once appeared on the bodywork of the car of another nation.  The winner of the 1924 Targa Florio in Sicily was a bright red Mercedes Tipo Indy and, being German, should have been painted in their racing color of white but, noting the rocks and other items the Italian crowd was inclined to throw at any machine not finished in Rosso Corsa, the team decided subterfuge was justified and the use of white by German entrants anyway didn’t last even a decade after the victory.

In 1934, with the Mercedes-Benz and Auto Union factory teams supported by the Nazi state as a propaganda project, the Mercedes-Benz W25s appeared in silver, the bare aluminum polished rather than painted.  For decades, the story told was that after a practice session, upon being weighed, the cars were found to be a kilogram-odd over the 750 KG limit for the event and the team had to work overnight to scrape off all the carefully applied, thick white paint, the weigh-in on the morning of the race yielding a compliant 749.9.  It was a romantic tale but has since been debunked, the race in question not being run under the 750 KG rule and in the 1990s, a trove of photographs was uncovered in an archive showing the cars arriving at the track unpainted, already in bare silver.  The authorities did request the Mercedes-Benz and Auto Union teams revert to white but already motorsport’s prime directive of the 1930s was operative: "Give way to the Germans".  That race in 1934 was the debut of the “silver arrows” but it happened not quite as the legend suggested.  Even the factory now refers to the tale as "the legend".

The International Organization for Standardization (ISO) has issued standard (ISO 11664-3:2019) which defines the technical terms and the colorimetric equations necessary for colorimetry and in that cobalt blue has been defined as Hex triplet #0047AB; sRGBB (r:0; g:71; b:171) & HSV (h: 215°; s: 100%; v:67%).  However, among manufacturers it’s often just a vague descriptor on the color chart and like many colors is treated as a spectrum with hues varying in shade and tone.  In the fashion industry there’s no attempt whatever at standardization or even consistency and the same house has been known to describe the fabric used in one range “cobalt blue” while in another line it might be “ultramariine”, “Prussian blue” “royal blue” or anything else which seems to suit.

Lindsay Lohan in cobalt blue dress at Nylon Magazine's launch of the Young Hollywood Issue, Tenjune, New York, May 2007.

The cobalt bomb is a speculative nuclear weapon, first suggested in 1950 by one of the leading physicists associated with the Manhattan Project which during World War II (1939-1945) developed the world’s first atomic bombs.  It was the implications of the cobalt bomb which first gave rise to the doomsday notion that it might be possible to build weapons which could kill all people on earth.  The device would be constructed as a thermo-nuclear weapon consisting of a hydrogen (fusion) bomb encased in cobalt which upon detonation releases large quantities of radioactive cobalt-60 into the atmosphere and from the site of the explosion it would be dispersed worldwide by atmospheric processes.  Because of its half-life, were the volume of the release to be sufficient, the entire planet could be affected well before radioactive decay reached the point where human (and almost all animal) life could be sustained.  It’s believed no full-scale cobalt bomb was ever built but the British did test the concept on a tiny scale and few doubt the major nuclear weapons powers have all simulated cobalt bombs in their big computers and, awesome of awful depending on one’s world view, the thing has long been a staple in science fiction and the genre called “nuclear war porn”.

The descendent of the idea was the neutron bomb which, like the cobalt device, relied for its utility on fall-out rather than the initial destructive blast.  The Pentagon-funded work on the first neutron bomb was conducted under the project name “Dove” (which seems a nice touch) and the rationale was that for use in Europe, what was needed was a weapon with a relatively low blast but which produced a nasty but relatively short-lived fallout, the idea being that there would be a high death-rate among an invading army but little physical damage to valuable real estate and infrastructure.