Diamond Mica Mine, Keystone, Keystone Mining District, Pennington County, South Dakota, USA

VERY FINE, sharp, pearlescent, tan to brown, highly lustrous, hexagonal muscovite book from the famous Diamond Mica Mine, South Dakota. Thin, individual layers are totally transparent. 8.3 x 5.5 x 0.7 cm

© Rob Lavinsky & irocks.com

Muscovite crystal on matrix. Total specimen size approximately 6 cm x 5.5 cm.

© Stephen E. Fritz

Approximately 25 cm muscovite crystal in quartz. South Dakota School of Mines & Technology Museum of Geology.

© Stephen E. Fritz

Crystal of muscovite. Collected by Richard Gillespie, Rolf Luetcke specimen and photo.

Crystal of muscovite. Collected by Richard Gillespie. Rolf Luetcke specimen and photo.

A 0.8 cm deep muscovite book from the Diamond Mica Mine in Keystone, South Dakota. I received this on December 7, 2020 from Tracy Wetter (Kennett Square, Pennsylvania). It came with one label from Ward's Natural Science Establishment, Inc.

© Alexander Wong