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Smithsonite is a mineral, named after James Smithson, the founding donor of the Smithsonian. He was an English scientist who lived c. 1765-1829. In a secondary clause in his will, he left his fortune to the United States of America—a place he never visited—to create “an establishment for the increase and diffusion of knowledge among men.”
The chemical name for smithsonite is zinc carbonate (ZnCO3), and it is one of a group of ores that yield the metal zinc. It was named in honor of Smithson because it was he who first identified the mineral in 1802.
When Smithson began to conduct his experiments on zinc ores, there was much confusion surrounding the mineral that at that time was known generally as calamine. Miners and metalworkers had long known that some kinds of calamine produced zinc, while other specimens—which contained zinc and appeared identical—did not. Smithson’s analysis revealed that what was called “calamine” was not in fact a single substance but essentially two distinct minerals: zinc carbonate (which was later named smithsonite) and zinc silicate (which came to be called hemimorphite). He identified the carbonate as a good ore for zinc and the silicate as a poor one.
Smithson’s analysis was published as an article in the prestigious Philosophical Transactions of the Royal Society and was widely praised. It was seen as a model for applying chemistry to the study of mineralogy, which were mostly separate disciplines at this time. And although he didn’t call attention to it, Smithson’s paper also contained a technique that would have been of great practical benefit to miners and brass manufacturers.
One of the problems with zinc ores, especially the forms of calamine that Smithson identified, was that they were often difficult to tell apart. Smithson developed a simple test that miners could use to identify which was which. It used a small but powerful tool called a blowpipe, an oil lamp, and a piece of charcoal.
Watch a chemist recreating Smithson's blowpipe test:
The blowpipe was a difficult tool to master, and Smithson was widely admired for his skill in using it. In order to maintain a steady flame, one had to breathe in through the nose while at the same time blowing out through the mouth. One also had to develop a familiarity with a wide range of effects in order to understand how particular materials reacted to the flame. Smithson was also known for his manipulation of miniscule quantities. He boasted of experimenting on “particles little more than visible” and took great pleasure in “the great beauty of deriving knowledge from so diminutive a source.” His work on the zinc ores exemplified not only his technical skill but also the depth of his understanding, both of which are still honored today through the mineral smithsonite.
See some of the different examples of smithsonite from the collections of the National Museum of Natural History:
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