The turquoise was filled with a mixture of crushed pyrite and polymer. Photo by C.D. Mengason. The Carlsbad laboratory recently examined a 78.60 ct greenish blue oval bead with patches that contained ...

This ancient gem contains three minerals in varying amounts: lazurite, calcite, and pyrite. Sometimes, it also contains one or more of the following: diopside, amphibole, feldspar, and mica. Lapis ...