Tourmaline in Muscovite (South Dakota!) Kay Robertston Coll.

Item Description

Surprising indicolite tourmalines from this extinct Keystone District, South Dakota pegmatite mine. One usually thinks of famous California or New England pegmatites for US indicolites, not South Dakota. The large laminated, pearlescent, muscovite plate hosts scattered tourmalines on both sides. The striking large tourmaline on the front is 4.0 cm. The gemmy to translucent crystal has fine teal-blue color. The smaller crystals on both sides are indicolites, indicolite and schorl and schorl. Ex Kay Robertson Collection # 621 and acquired in the early 1950s, with the low collection number. Kay is a prominent California collector, who specialized in European classics (see the article in the March-April, 2007 Mineralogical Record). Very rare on the market today. A must for the locality or species collector.