R.V. Dietrich
Contributor
LOCATION: Mt. Pleasant, MI, United States
Emeritus Professor of Geology, Central Michigan University, Mount Pleasant. Author of Stones; coauthor of Gems, Gravels and Granites.
Primary Contributions (6)
Mica, any of a group of hydrous potassium, aluminum silicate minerals. It is a type of phyllosilicate, exhibiting a two-dimensional sheet or layer structure. Among the principal rock-forming minerals, micas are found in all three major rock varieties—igneous, sedimentary, and metamorphic. Of the 28…
READ MORE