At first glance, bismuth doesn’t seem to be particularly extraordinary. Element number 83 is probably most likely encountered in the compound bismuth subsalicylate (C7H5BiO4), used in gastro-intestinal remedies such as Pepto Bismol. The pure metal is also gaining popularity as a more environmentally friendly (and much more expensive) alternative to lead in hunting ammunition. In these forms, it is understandable how bismuth can be considered boring. If the metal is allowed to properly crystallize  though, you can get some truly fascinating objects.

A crystalline sample of bismuth, grown in Germany.

A crystalline sample of bismuth, grown in Germany.

The interesting shape (which has always looked somewhat futuristic to me) comes from the crystalline nature if the metal itself. The color comes from a thin oxide layer.

Bismuth marks a milestone on the periodic table. It was long believed that bismuth was the heaviest of the stable elements, as evidenced by the fact that everything beyond element 83 is very noticeably radioactive (the element immediately adjacent to bismuth on the table, polonium, is a particularly nasty one). Moreover, the naturally-occurring isotope, Bi-209, never showed any signs of radioactivity, though some calculations suggested it shouldn’t be stable. In 2003, it was finally proven that bismuth was, in fact, the lightest naturally-occurring radioactive element, undergoing alpha decay into thallium-205 with a half-life of 1.9×1019  ( that’s nineteen quintillion, or 19,000,000,000,000,000,000) years, which is approximately one billion times the current estimated age of the universe. Needless to say, bismuth can be considered stable for virtually all purposes. That much can’t be said about any element beyond here.

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