Had the stone for a few years now... I dont know anything about it or any other gems or stones... any input would be great.
Quartz has no cleavage and feldspars have good cleavage in three directions. Quartz is harder than feldspars (7 vs. 6). This means that quartz is more likely to remain intact than feldspars. Minerals with cleavage can separate along those cleavage planes and feldspars turn into clays. Clays are an important part of soils. Quartz turns into sands that end up as dunes, although some sands do make their way in soils.
feldspar is chemically reactive and breaks down and turns into clay. So the amount of clay in soils is related to the amount of feldspar and other silicate minerals. Quartz, silicon dioxide is very stable and will not change composition over millions of years.
