This is the greenish-gray tinguaite sphere. Diameter 2.2″ (57mm). Weight – 9.7oz (276 grams). Origin: Russia, Kola Peninsula.
Some information about tinguaite:
Tinguaite is an undersaturated, medium-to coarse-grained, igneous rock consisting of essential alkali feldspar, nepheline, and aegirine (with or without sodic amphibole or biotite). Tinguaite is the hypabyssal equivalent of phonolite.