This is the blue violane brooch. Dimensions: 2.0 x 1.5 x 0.2″ (5.1 x 3.7 x 0.6cm). Weight – 0.6oz (16 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.