This is the blue violane ring. American ring size 8 1/2. Dimensions: 1.1 x 0.8 x 0.2″ (2.7 x 2 x 0.6cm). Weight – 0.2oz (6 grams). Origin: Russia, Transbaikalia.
Some information about violane:
Violane is a variety of the diopside mineral bluish tones. Violane color is due to admixture of manganese and iron. Contains 10% jadeite and aegirine components.
Known deposits from Italy (Saint-Marcel, Piedmont) and Russia. In Russia deposits are located in the Transbaikalia, Altai and Sayan.