This is the yellow-green ophicalcite cabochon. Dimensions: 2.1 x 1.0 x 0.2″ (5.3 x 2.6 x 0.5cm). Weight – 0.3oz (9 grams). Origin: Russia, Siberia.
Some information about ophicalcite:
Ophicalcite is a serpentinite breccia popular since ancient times as a decorative facing stone. It is a dark, dull green, white-mottled (or white-veined) serpentine, mixed with calcite, dolomite, or magnesite, which takes a high polish. It is sometimes classed, erroneously, as a variety of marble.
Non-brecciated varieties of a very similar serpentinite, sometimes also called “verd antique”, have been quarried at Victorville, California; Cardiff, Maryland; and Rochester in Addison County, Vermont.