Amethyst Galleries
Amethyst Galleries: Mineral Gallery: The Mica Group
The mineral mica is actually a group of over thirty minerals from the subgroup Silicates. This website lists each one and provides detailed information on the most common mica minerals.
Amethyst Galleries
Amethyst Galleries: Mineral Gallery: What Is Crystal Cleavage?
After explaining the difference between cleavage and fracture, this resource discusses various types of cleavage and their importance in identifying minerals.