Strontium

Strontium takes its name from Strontian, a village in the western Highlands of Scotland where the mineral strontianite was found in a lead mine; the new earth in it was recognised in the 1790s, and the metal was isolated by Humphry Davy in 1808. It is the only element named after a place in the United Kingdom. Strontium is a soft, silvery alkaline-earth metal, best known for the vivid crimson it lends to fireworks and flares. Strontium salts burn with a characteristic red flame, the source of the reds in pyrotechnics and warning flares, and were long used in the glass of cathode-ray television tubes; the pure metal itself has few structural applications.

Strontium aluminate compounds are the active ingredient in most modern glow-in-the-dark pigments, absorbing light and releasing it slowly in the dark for hours, a safer successor to the radium-based luminous paints once used for the same effect before radium's radioactivity was understood to be dangerous. In medicine, strontium ranelate was developed and marketed in the 2000s as a treatment to strengthen bone in osteoporosis, since strontium can substitute for calcium in bone mineral, though later evidence of increased cardiovascular risk led European regulators to sharply restrict its use.

Strontium's name is a quiet piece of Scottish geography embedded in the periodic table, honouring the mining village whose ore first yielded it. The element gained a darker modern significance in the twentieth century, when the radioactive isotope strontium-90, produced in nuclear fission and spread by atmospheric bomb tests, was found to lodge in bones and teeth in place of calcium, becoming one of the most feared fallout products of the atomic age and a focus of the campaign to end open-air testing.

Strontium thus joins a Highland place-name to a Cold War anxiety, with its cheerful red firework flame standing between the two. Public alarm over strontium-90 was sharpened by the Baby Tooth Survey, a study begun in St. Louis in 1958 that collected tens of thousands of children's shed baby teeth to measure the fallout isotope accumulating in their bodies; the rising strontium-90 levels the survey documented helped build the public and scientific pressure that led to the 1963 Partial Test Ban Treaty, which moved American, Soviet and British nuclear testing underground. Strontianite, the mineral that started the whole story, remains a modest curiosity today, quarried in only a few places worldwide compared with the far larger celestite deposits that now supply most strontium.