James Madison University
James Madison University: Mineral Hardness and Cleavage
An explanation of the Mohs Hardness scale is followed by illustrations of crystal structures and cleavage.
CK-12 Foundation
Ck 12: Earth Science: Mineral Identification
[Free Registration/Login may be required to access all resource tools.] Classifying minerals based on physical characteristics.
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.