Feldspar

Feldspar is the name of a group of rock-forming tectosilicate minerals that make up as much as 60% of the Earth's crust.
Feldspar forms crystals from magma in both intrusive and extrusive rocks, and they can also happen as compact minerals, as veins, and are also present in many types of metamorphic rock. Rock formed entirely of plagioclase feldspar is known as anorthosite. Feldspar is also found in many types of sedimentary rock.
Feldspar is typically reddish or pale pink in color, and has a hardness of 6 on the Mohs scale, making it roughly as hard to scratch as glass.
There are two groups of feldspar, both made out of silica and aluminum: