Tourmalines 2017 02
Tourmaline: Yellow and Green
Guess which one is copper bearing.
This month we feature two exceptional tourmalines that redefine what we think of as cuprian. Cuprian or copper bearing is a relatively new variety of tourmaline that first popped up in Brazil, then Nigeria, and most recently Mozambique. We generally associate copper with paraiba varieties in the blue to greenish blue hues but there is quite an array of colors that can stem from copper or a mix of copper and other chromophores. But we definitely know that copper produces neon and fluorescent-like properties in tourmaline.
The copper-bearing tourmaline in this picture is in fact the 43.40-carat yellow while the 38.54-carat blue green one is void of copper but still holds a beautiful glow from an alternate mixture of elements.
The 38.54-carat blue-green tourmaline (Inv. #23645) certainly has a special chemical blend that produces this unique color. It's hard to pinpoint locality on this one with colors reminiscent of Brazil, Afghanistan, and Namibia. Recent feedback in Tucson places it from the Usakos region of Namibia.
The 43.40-carat yellow tourmaline (Inv. #23616) was found to have traces of copper and manganese, which most likely sources it from Mozambique. Mozambique produced a wide variety of hues containing copper, from the classic blue to blue greens, along with greens, purples, magentas, violets, and now yellow!