A purple-colored 1M mica clay from Silverton, Colorado

Clays and Clay Minerals



A purple-colored clay of 1M mica polymorph in association with lead-zinc ore was collected from an abandoned mine dump near Silverton, Colorado. Electron micrographs show that the crystallites of the clay are less than 2µ in size and have poorly developed hexagonal outlines. Differential thermal and i.r. absorption analyses indicate similarity with those of muscovite. The structural formula of the 1M mica polymorph is (K1.45 Na0.02) (Al3.75 Mg0.19) (Si6.90 Al1.10) O20(OH)4. The purple color may be related to trace amounts of manganese in the clay.

Publication type Article
Publication Subtype Journal Article
Title A purple-colored 1M mica clay from Silverton, Colorado
Series title Clays and Clay Minerals
DOI 10.1346/CCMN.1969.0170408
Volume 17
Issue 4
Year Published 1969
Language English
Publisher The Clay Minerals Society
Description 5 p.
First page 245
Last page 249
Country United States
State Colorado
City Silverton
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