2: Minerals
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- 2.4: Silicate Minerals
- The vast majority of the minerals that make up the rocks of Earth’s crust are silicate minerals. These include minerals such as quartz, feldspar, mica, amphibole, pyroxene, olivine, and a variety of clay minerals. The building block of all of these minerals is the silica tetrahedron, a combination of four oxygen atoms and one silicon atom. As we’ve seen, it’s called a tetrahedron because planes drawn through the oxygen atoms form a shape with 4 surfaces.
Thumbnail: A ball of lustrous, royal-blue cavansite blades is set on a starkly contrasting snow-white crust on basalt matrix on this fine specimen from recent finds at the Wagholi Quarry of India. (CC-SA-BY 3.0; Rob Lavinsky from iRocks.com).