Sinkankasite
Sinkankasite, mineral formula:, was named after John Sinkankas, noted author and mineral collector, Scripps Institute of Oceanography. It is triclinic; as colorless, bladed to prismatic crystals up to 4 mm in length, often as divergent, radial aggregates and as pseudomorphs after triphlyte crystals; occurs in the Barker pegmatite, east of Keystone, South Dakota, and in the Palermo pegmatite, North Groton, New Hampshire.
