A late phase in nepheline syenites, syenitic pegmatites, and along the contact zone of a differentiated alkalic massif.
IMA Status:
Approved IMA 1961
Locality:
Mt. Vavnbed, Lovozero massif, Kola Peninsula, Russia. Link to MinDat.org Location Data.
Name Origin:
Named for Kuz'ma Alekseevich Vlasov (1905-1964), founder of the Institute of Mineralogy, Geochemistry, and Crystal Chemistry of Rare Elements, Moscow, Russia.
Chemical Formula: 