Quartz-rock
111rock-crystal — /ˈrɒk krɪstl/ (say rok kristl) noun transparent quartz, especially of the colourless kind …
112quartz mining — noun : the mining of gold on veins or ore bodies in place as distinguished from surface digging or washing : underground mining in rock compare placer mining …
113Metamorphic rock — Metamorphic redirects here. For other uses, see Metamorphic (disambiguation). Quartzite, a form of metamorphic rock, from the Museum of Geology at University of Tartu collection. Metamorphic rock is the transformation of an existing rock type,… …
114sedimentary rock — Rock formed at or near the Earth s surface by the accumulation and lithification of fragments of preexisting rocks or by precipitation from solution at normal surface temperatures. Sedimentary rocks can be formed only where sediments are… …
115igneous rock — Any of various crystalline or glassy, noncrystalline rocks formed by the cooling and solidification of molten earth material (magma). Igneous rocks comprise one of the three principal classes of rocks, the others being metamorphic and sedimentary …
116metamorphic rock — Any of a class of rocks that result from the alteration of preexisting rocks in response to changing geological conditions, including variations in temperature, pressure, and mechanical stress. The preexisting rocks may be igneous, sedimentary,… …
117Sedimentary rock — Middle Triassic marginal marine sequence of siltstones (below) and limestones (above), Virgin Formation, southwestern Utah, USA Sedimentary rock are types of rock that are formed by the deposition of material at the Earth s surface and within… …
118Igneous rock — Geologic provinces of the world (USGS)   Shield …
119Clastic rock — A thin section of a clast (sand grain), derived from a basalt score. Vesicles (air bubbles) can be seen throughout the clast. Plane light above, cross polarized light below. Scale box is 0.25 mm Clastic rocks are composed of fragments, or clasts …
120Dynamic quartz recrystallization — Quartzite from Southern Appalachians. Thin section prepared by Michael Stevens. Quartz is the most abundant single mineral in the earth s crust (behind the feldspar group),[1] and as such is present in a very large proportion of rocks both as… …
