Demantoid [SEP] named after
is atypical for garnet. They began comparing it to diamond and referred to it as "demantoid", from the French "demant", meaning diamond. The reason is obvious, with its high brilliance and dispersion.
A second find was made 75 km. to the south of Ekaterinburg, on the Chusovaya and Chrisolitka Rivers southwest of the village of Poldnevaya. Deposits are also found underground up to 3 meters deep in the demantoid placier. In all, there are five deposits of demantoid in this area. Possessing an unusual green
Demantoid
Demantoid is the green gemstone variety of the mineral andradite, a member of the garnet group of minerals. Andradite is a calcium- and iron-rich garnet. The chemical formula is CaFe(SiO) with chromium substitution as the cause of the demantoid green color. Ferric iron is the cause of the yellow in the stone.
It has the misnomers "olivine", and "Uralian emerald".
In approximately 2003, reports began to circulate in the trade that some Russian demantoid garnets were being routinely subjected to heat