Thomas Jefferson is the only president of the United States to have his name given to an earth mineral: “Jeffersonite.” In 1822, in honor of Jefferson’s contributions to natural history, the naming and description of the mineral was presented in the Journal of the Academy of Natural Sciences of Philadelphia:^[1]

In the authoritative work, Dana’s Textbook of Mineralogy, Jeffersonite is described as "a manganese-zinc pyroxene [occurring] in large, coarse crystals with edges rounded and faces uneven. Color greenish black, on the exposed surface chocolate-brown.”^[2]  A search of specimens for sale disclosed the lowest cost of the rare mineral was $600, that for a specimen four inches in length.

- Edgar A. Imhoff, 9/23/13

Further Sources

• Mindat.org.  "Jeffersonite."