William Maclure, glauberite and the Academy of Natural Sciences of Philadelphia

In the 1820s, the American geologist William Maclure (1763-1840) spent some time in Spain. In June 1822 he was able to obtain a batch of glauberite specimens from the only known deposit of this mineral at the time, the salt mine of Villarrubia de Santiago (Toledo), Spain, which he sent to various American institutions. The closure of the mine meant that these were the only specimens of this mineral available to researchers around the world for several decades.eng