Bismuth exists in nature as a metallic form. Metallic bismuth can be extracted from its oxide ores using carbon reduction. Due to its relatively simple extraction process, it is speculated that its discovery predates nitrogen (1772) and phosphorus (1669), and that humans may have even obtained metallic bismuth during the Middle Ages. However, bismuth has long been mistakenly considered a derivative of lead, tin, or antimony, and has not been identified as an independent element.
In the 15th century, Germany possessed a technique for producing metallic bismuth by thermally reducing bismuth oxide or bismuth sulfide with coke. This metal was used as a protective base layer in coatings on metal objects. With the advancement of the coating industry, the uses of bismuth gradually expanded, particularly becoming an important component in printing alloys. However, at that time, bismuth was generally still classified as one of the three "forms" of lead, considered alongside tin and lead as different manifestations of the same metal.
The 16th-century physician and alchemist Paracelsus (1493-1541) distinguished between two types of antimony: one black, used for gold extraction, and similar to lead; the other white, actually bismuth, but confused due to its resemblance to tin. At the time, Saxon miners also smelted bismuth from ore, but mistakenly believed it to be a tin-like variant of lead. This demonstrates that bismuth's independent status was not established for a long time.
Despite the prevailing misconception about bismuth's elemental status, a few scholars began to assert its independence by the mid-16th century. The renowned German metallurgist Agricola (1494-1555), in his seminal work *Metallurgy*, explicitly argued that bismuth was not a variant of lead or tin, but a metal with unique properties. This view surpassed the consensus of most scholars at the time. Notably, even into the 18th century, some still denied bismuth's independence. For example, in the *Proceedings of the French Academy of Sciences* (1713), some described bismuth as a complex mixture of sulfur, mercury, arsenic, and earth.
In 1753, C. J. Geoffroy's posthumous work, *Chemical Analysis of Bismuth*, was formally published. The book systematically demonstrated the differences in properties between bismuth and lead, and for the first time explicitly defined it as an independent metallic element. It is now widely believed that the concept of bismuth as an independent metal was gradually established in the academic community after the publication of this work.
In 2003, scientists successfully detected the α-decay of 209Bi in a bismuth germanate detector cooled to 20 mK, measuring an energy release of 3.137 ± 1 ± 2 keV and a half-life of (1.9 ± 0.2) × 10¹⁹ years, consistent with the theoretically expected half-life, proving that natural bismuth possesses weak radioactivity.
