Shale

Shale is a sedimentary rock composed of very fine clay particles. Clay forms from the decomposition of the mineral feldspar. Other minerals present in shale are quartz, mica, pyrite, and organic matter. Shale forms in very deep ocean water, lagoons, lakes and swamps where the water is still enough to allow the extremely fine clay and silt particles to settle to the floor. Geologists estimate that shale represents almost ¾ of the sedimentary rock on the Earth’s crust.

Geologists are specific about the definition of the rock called “shale.” Shale is composed of clay particles that are less than 0.004 mm in size.

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Description

Shale is a sedimentary rock composed of very fine clay particles. Clay forms from the decomposition of the mineral feldspar. Other minerals present in shale are quartz, mica, pyrite, and organic matter. Shale forms in very deep ocean water, lagoons, lakes and swamps where the water is still enough to allow the extremely fine clay and silt particles to settle to the floor. Geologists estimate that shale represents almost ¾ of the sedimentary rock on the Earth’s crust.

Geologists are specific about the definition of the rock called “shale.” Shale is composed of clay particles that are less than 0.004 mm in size.

Relation to Mining

Typically, common clays and shales are dug from open pits, and these pits must be near the processing plants to minimize production costs. Most products made from these materials are processed and marketed in a similar manner to refractory clays. Common clays and shale require little processing. Typically they are crushed or ground.