Gem Virtuosos: The Drehers and Their Extraordinary Carvings
A look at the artistic heritage of the Drehers, an influential family of gem carvers in Idar-Oberstein, Germany.
The 3543 CM-1 Infrared Absorption Band in Natural and Synthetic Amethyst and its Value in Identification
The proper use and limitations of IR spectroscopy for identifying natural versus synthetic amethyst of various types have been investigated, focusing on the region 3800–3000 cm-1.
Amethyst from Four Peaks, Arizona
For more than a century, the Four Peaks mine in Maricopa County, Arizona, has produced gem-quality amethyst.
Amethyst Mining in Brazil
Brazil is currently the leader in overall production of amethyst.