This is the green river nephrite pebble. Dimensions: 4.1 x 2.5 x 1.0″ (10.5 x 6.4 x 2.5cm). Weight – 8.7oz (248 grams). Origin: Russia, Siberia.
Some information about nephrite:
Nephrite is a variety of the calcium, magnesium, and iron-rich amphibole minerals tremolite or actinolite. It is one of two different mineral species called jade. The other mineral species known as jade is jadeite, which is a variety of pyroxene. While nephrite jade possesses mainly grays and greens (and occasionally yellows, browns or whites), jadeite jade, which is rarer, can also contain blacks, reds, pinks and violets.
Nephrite can found in a translucent white to very light yellow form which known in China as mutton fat jade, in an opaque white to very light brown or gray which known as chicken bone jade, as well as in a variety of green colors.
Nephrite gets its name from Greek “nephros” – kidney, ancient people believed nephrite to treat kidney diseases.