mud - soil with mud, muck, or mire; The child mucked up his shirt while playing ball in the garden muck up, muck, mire begrime, bemire, colly, dirty, grime, soil - make soiled, filthy, or dirty; don't soil your clothes when you play outside!
Quartz is one of the most common minerals in the Earth's crust. It is made up of silicon dioxide (SiO2), otherwise known as silica. White sand is primarily made from quartz. Click here to find out more.
Natural abundance. Silicon makes up 27.7% of the Earthâs crust by mass and is the second most abundant element (oxygen is the first). It does not occur uncombined in nature but occurs chiefly as the oxide (silica) and as silicates. The oxide includes sand, quartz, rock crystal, amethyst, agate, flint and opal. The silicate form includes asbestos, granite, hornblende, feldspar, clay and mica.