what are the seven common rock forming minerals
The six minerals olivine, quartz, feldspar, mica, pyroxene and amphibole are the commonest rock-forming minerals and are used as important tools in classifying rocks, particularly igneous rocks. Except for quartz, all the minerals listed are actually mineral groups.lagioclase. Feldspar: Feldspar is the other common, light-coloured rock-forming mineral. Instead of being glassy like quartz, it is generally dull to opaque with a porcelain-like appearance. Colour varies from red, pink, and white (orthoclase) to green, grey and white (plagioclase).