How the character is built
The 钅 radical marks this as a metal, and that is not a coincidence of this one character — it holds right across the table. Read the radical first and the element's state at room temperature is already settled. It is 金 (jīn) squeezed into the space beside another component — radicals change shape by position, which is why 金 is hard to spot until you know to look for 钅.
This character is used for the element and little else — you are unlikely to meet it outside a chemistry classroom.
The element itself
Cobalt is named after a goblin. German miners in the Erzgebirge kept hitting ore that looked like valuable silver, yielded no metal when smelted, and released choking fumes — the arsenic it was bound up with — and they blamed the kobold. The blue it gives to glass and porcelain is one of the most stable pigments ever found, unchanged in ceramics that are centuries old. Most cobalt today is a by-product of copper and nickel mining, and by far the richest concentration lies in the Central African Copperbelt.
Where it sits among the 118
First isolated in 1739.
In living things
Cobalt appears in the human body in exactly one setting: at the centre of vitamin B12, held in a corrin ring that looks like a slightly squashed relative of heme. What makes it remarkable is the bond from cobalt to a carbon atom — the only stable metal–carbon bond in biology, and one weak enough to be snapped homolytically to launch some very strange radical rearrangements. No plant or animal can build the molecule; only bacteria and archaea make it, which is why the vitamin reaches most animals either through what they eat or through the microbes fermenting in their own gut.
In Chinese history and language
The blue of blue-and-white porcelain, 青花 qīnghuā, is cobalt, and the earliest and most admired of it was not Chinese at all: Yuan and early Ming painters worked with cobalt imported from West Asia, known as 苏麻离青 sūmálíqīng. That ore ran high in iron and low in manganese, which is exactly why the great early wares have their deep violet-blue and the pooled black flecks connoisseurs call heaping and piling. Domestic Jiangxi ores took over around the middle of the fifteenth century — more manganese, less iron, and a softer, greyer, more even blue that is a different aesthetic rather than a failed imitation.
Where it comes from in China
Cobalt is the element where Chinese geography matters least. What the country mines itself is a modest by-product, mostly from the nickel sulfides at Jinchuan in Gansu, since cobalt follows nickel through the same sulfide melt. Its refining industry is a separate matter from its rocks: most of the ore that industry treats was mined elsewhere, and cobalt is almost never the reason a mine exists in the first place.
The full entry
For stroke order, example sentences, audio and the complete set of meanings, see the dictionary entry.
钴Cobalt in the dictionary →Others built the same way
Every one of these carries 钅, and every one is a metal.