Tourmalines: A Family of Many Colors
Tourmaline has been an admired gem for centuries, even if misidentified as ruby in some of the crown jewels. Tourmaline is actually a group of minerals with a common structure, but with different chemical compositions. There are currently more than 30 known members of this family, and at least five of them have found their way into the word of gems. Joins us for this summer's gemological lecture as Dr. George Rossman explores the tourmaline family, its properties and the mines from which it comes.
George Rossman is Professor of Mineralogy at the California Institute of Technology in Pasadena. He researches the origin of mineral's color, and how properties such as color respond to natural variables such as temperature, pressure and natural background radiation.