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.
Where you actually meet it
镁光灯 (měiguāngdēng) magnesium flashlamp, figuratively the media spotlight
The element itself
Magnesium is the lightest metal in common structural use, and it burns with a white glare that photographers exploited before flashbulbs existed. Alone among industrial metals, a large share of it was once taken straight out of seawater — a cubic kilometre of ocean holds something over a million tonnes of dissolved magnesium, and the extraction is simply a matter of precipitating it out. The other route is the mineral dolomite, roasted and reduced at high temperature, which is how most of the world's magnesium is made today.
Where it sits among the 118
First isolated in 1755.
In living things
Magnesium sits at the centre of every chlorophyll molecule, four nitrogen atoms gripping it in a flat ring — the green of the world is a magnesium complex. Inside cells it does quieter structural work: ATP is almost never handled bare, and enzymes recognise the magnesium–ATP complex rather than the nucleotide itself, because the metal's double positive charge tames the phosphate chain's own repulsion. RNA depends on the same trick, since a folded ribosome packs negatively charged backbone against negatively charged backbone and only holds that shape with magnesium ions threaded through to screen the charge.
In Chinese history and language
Nephrite is a solid solution running between a magnesium end and an iron end, and that ratio is precisely what a jade buyer is judging by eye. More iron gives the greens, from pale celadon to spinach-dark; the magnesium-rich end is white and faintly waxy-translucent, and that is the celebrated 羊脂玉 yángzhīyù, "mutton-fat jade", the most prized Hetian material of all. A thousand years of connoisseurship, expressed mineralogically, is a settled preference for magnesium over iron.
Where it comes from in China
Magnesium's Chinese address is Haicheng and Dashiqiao in Liaoning, where an enormous body of magnesite sits in Precambrian metamorphic rock — one of the great concentrations of that mineral anywhere. Most of it becomes refractory brick rather than metal, because magnesia survives temperatures that destroy other furnace linings. Magnesium appears in a quite different Chinese context too: nephrite jade, the stone prized above all others, is a calcium-magnesium silicate, and the classic source is the Kunlun range in Xinjiang, where boulders were gathered from the rivers below Hotan.
The full entry
For stroke order, example sentences, audio and the complete set of meanings, see the dictionary entry.
镁Magnesium in the dictionary →Others built the same way
Every one of these carries 钅, and every one is a metal.