1. Quartz: This is the most common mineral found in granite, giving it its characteristic glassy sparkle. Quartz is clear, colorless, or white, but can also appear in shades of pink, gray, and brown.
2. Feldspar: The second most abundant mineral in granite, feldspar accounts for approximately 60% of the rock's composition. It can be either potassium feldspar (orthoclase) or plagioclase feldspar, both of which contribute to the white, pink, or cream color of many granites.
3. Mica: This group of minerals gives granite its characteristic sheen. Biotite mica is dark brown to black, while muscovite mica is silvery white to pale gray.
4. Amphibole: Hornblende is the most common amphibole found in granite. This mineral has a dark green to black color and often appears in elongated crystals.
Other Minerals: While the four main minerals above are most prevalent, trace amounts of other minerals may also be present in granite, including:
* Pyroxene: Dark green to black minerals that can be found in small amounts.
* Apatite: A phosphate mineral that can add a blue-green color to granite.
* Zircon: A hard, transparent mineral with a high refractive index.
* Magnetite: A black iron oxide that can be found in small, magnetic grains.
* Ilmenite: A black titanium oxide mineral.
The exact mineral composition of granite can vary depending on the source of the magma and the conditions under which it cooled. However, the presence of these minerals in varying proportions is what gives granite its unique characteristics.
