Strontium

Strontium is named after Strontian, a village in the Scottish Highlands where the mineral strontianite was found in 1790 — the only element named for a place in Britain. Strontium salts give the deepest red in pyrotechnics and emergency flares, and strontium aluminate is the long-glow phosphor in modern luminous exit signs. Its dark side is strontium-90, a fission product with a 29-year half-life that behaves chemically like calcium and therefore deposits in bone. In the late 1950s the Baby Tooth Survey in St Louis collected over 300000 shed milk teeth and showed that strontium-90 levels in children born in the 1960s were roughly fifty times those born before atmospheric testing began; the data fed directly into the 1963 Partial Test Ban Treaty. Strontium optical lattice clocks are now the most accurate timekeepers ever built.