Common Rock-Forming Minerals
- Amphibole
- A group of dark minerals containing iron and/or magnesium and
silica
- Biotite
- "Black" mica. Dark-colored sheet silicate mineral found in
igneous and metamorphic rock.
- Feldspar
- A group of light minerals containing alkali metals (sodium,
calcium, potassium) and silica
- Garnet
- Aluminum silicate mineral found in igneous and metamorphic rock.
Colors: dark red, pink, light green. Some forms semi-precious.
- Kyanite
- Light blue aluminosicate mineral found in metamorphic rocks, often
in schist. Used in high-temperature ceramics.
- Mica
- Sheet silicate mineral found in igneous and metamorphic rock.
- Muscovite
- "White" mica. Light-colored sheet silicate mineral found in
igneous and metamorphic rock.
- Orthoclase
- Variety of feldspar.
- Plagioclase
- Variety of feldspar.
- Pyrite
- Iron sulfide. Mineral usually found in metamorphic rock,
particularly remnants of submarine hydrothermal vents. Usually
gold color. Combines with oxygen and water to form sulfuric acid.
- Quartz
- Crystalline silica. Translucent; transparent when pure. Major
component of many minerals, e.g. amethyst, citrine, agate,
chalcedony.
- Silica
- Silicon dioxide. The most abundant mineral on earth. Found in
most rocks; combines to form many other minerals (silicates).