This check would not work, however, if the mineral is harder than porcelain. Color is important, but by itself, colour doesn’t positively identify a mineral. The classic example is iron pyrite, which has a color that resembles gold so carefully that folks name it idiot’s gold. Color does help identify some rocks, such as the monochromatic azurite with its deep azure colour, but many minerals have combinations or colours or hues attributable to the presences of impurities.
This banding has alternating layers which might be composed of different minerals. The minerals that compose gneiss are the identical as granite. Feldspar is the most important mineral that makes up gneiss along with mica and quartz.
Gneiss may be shaped from a sedimentary rock corresponding to sandstone or shale, or it may be fashioned from the metamorphism of the igneouse rock grantite. Gneiss can be used by man as paving and building … Read More