Here we have examples of common minerals that are categorized by type. Each has a thumbnail picture of the specimen and a brief description of it. Clicking on the name of the individual specimen will take you to a page with a larger picture and a detailed description.
The Silicates |
 | Amazonite is a beautiful green variety of microcline feldspar. Its chemical formula is KAlSi3O8 , potassium aluminum silicate. |
 | The Mica Group is the name given to a group of silicate minerals that have silicon and oxygen as their two major components. |
 | Muscovite is a member of the mica mineral group. It is more important as a rock-forming mineral than as a collectible specimen. |
 | Biotite Biotite is a member of the mica branch of the silicate mineral group. It is common as a rock-forming mineral and is present in all three rock types: igneous, metamorphic, and sedimentary. |
Quartz Family |
 | Quartz is one of the most common of all minerals that make up the continental crust. It is found in igneous, metamorphic, and sedimentary rocks. It is associated with many valuable ore deposits as well. |
 | Amethyst is a variety of quartz and owes its purple color to the presence of iron. It is composed of silicone dioxide SiO2. |
 | Agate is the name given to a group of silicates that are made up primarily of chalcedony. Chalcedony is a member of the quartz family of minerals. Like quartz chalcedony is silicone dioxide with a chemical formula of SiO2. |
 | Tigers Eye is a form of quartz with some special characteristics. Like all quartz it is made up primarily of silicone dioxide, SiO2. Within this matrix are asbestos fibers usually occurring in layers. It is the asbestos that makes Tiger eye a chatoyant gemstone. |
The Sulfates |
 | barite is a sulfate mineral with a chemical formula of BaSO4, sometimes called heavy spar. Its chemical name is barium sulfate. It is the primary source of the element barium. |
 | Celestite is made up of strontium sulfate. The chemical formula is SrSO4. Its name comes from Latin, caelestis meaning celestial. |
The Carbonates |
 | Rhodochrosite is a manganese carbonate mineral. Its chemical composition is MnCO3. In its purest form it is a transparent rose red, but this is fairly rare. It can also be formed in stalactites. This form can be sliced revealing circular layers of rose and pink to milky white. These lighter colors are formed when the manganese is replaced by calcium, manganese or zinc. The depth of color from red to pink depends on the amount of substitution. |
 | Azurite is a copper carbonate mineral. The chemical formula is Cu3[OH CO3]2and results from the oxidation of copper sulfides. |
 | Malachite is a copper carbonate mineral with a chemical formula of Cu2[(OH)2 CO3]. It is a vibrant green color often banded with light and dark greens. |
The Oxides |
 | Magnetite is sometimes called lodestone. It is strongly magnetic. It was used by the ancient Chinese to make the first magnetic compasses. The chemical formula is Fe3O4. |
The Halides |
 | Fluorite Fluorite is a halide mineral that is soft and usually colorless but can be blue, purple, green, brown, or yellow. Some times several colors are present in the same crystal creating a striking affect. |
The Sulfides |
 | Galena has been mined for lead and silver since the time of the Romans. It is a form of lead sulfide. The chemical formula is PbS. It is the most important source of lead and is abundant and widespread in occurance. |
 | Stibnite Stibnite is a sulfide mineral found in low temperature hydrothermal veins and hot springs deposits. It is prized by collectors for the long slender bladed crystals. These can occur in clumps with many orthorhombic crystals radiating in all directions. It is very soft only a 2 on the Mohs hardness scale. |
 | Pyrite sometimes called iron pyrite is a compound of iron and sulfur, iron sulfide FeS2. Depending upon the conditions under which it forms pyrite can form crystals of different shapes. |
Elements |
 | Bismuth Crystals Bismuth in its elemental form is a rare occurance in nature, even more so for bismuth crystals. Lab grown crystals are popular because of their intricate shapes and dazzaling colors. |
