This is the blue violane brooch. Dimensions: 1.6 x 1.1 x 0.2″ (4 x 2.8 x 0.6cm). Weight – 0.5oz (14 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.