This is the green-brown nephrite sphere. Diameter 2.6″ (67mm). Weight — 16.7oz (474 grams). Origin: Russia, Siberia.
Some information about nephrite:
This stone is really well-known, it was very popular in ancient time, especially in Egypt and China. Many centuries ago people carved amulets from nephrite, they even made nephrite coins.
Nephrite is in fact a fine-grained, calcium-rich, magnesium, iron, aluminous amphibole. It is composed of highly intergrown, interlocking (matted or felted texture, like asbestos or felt) crystals. Though this stone is not very hard (its hardness is from 5 to 6,5 Moh’s Scale depending on the deposit), nephrite is one of the toughest gem minerals known because of the intergrown nature of the individual crystals.
Nephrite gets its name from Greek “nephros” – kidney, ancient people believed nephrite to treat kidney diseases. Numerous deposits of this material are spread around the world, there are mines in British Columbia (Canada), in China, Australia, New Zealand, Taiwan and Alaska. The history of nephrite in Russia begins in 15th century, when it was brought from Central Asia by merchants. First nephrite mine in Russia, in Sayany mountains near the Baikal lake, was found only in 18th century.