Utah State Office of Education
Utah State Office of Education: Identifying and Classifying Minerals
This thorough Utah State Office of Education site explains the criteria for identifying minerals and provides pictures of various minerals.
Children's Museum
Children's Museum of Indianapolis: What's a Hardness Scale?
Find an illustrated explanation of the Mohs' hardness scale, which is used to compare the hardness of minerals. The scale explains the differences in hardness among a range of minerals, beginning with the softest (talc) and ending with...