Name A list of minerals in alphabetical order By Class Elements, Oxides, Carbonates, etc. Interesting Groupings Gemstones, Birthstones, etc. Physical Properties Keys to identifying minerals Full Text Search Mineral identification by keyword searching As colorful as the rainbow and as sparkling as fine leaded crystal, gemstones have captured the imaginations and desires of men and perhaps especially, women, for ages. Today, more fine gemstone specimens are available to the average person than at any time in history. Fluorite is extremely colorful and pretty but has a hardness of only 4 on the Moh's hardness scale and has four perfect cleavage directions, which makes it only an oddity as a cut gem.
Most gems are silicates which can be very stable, hard minerals.
A few gems are oxides and only one gem, diamond, is composed of a single element, carbon.