### Garnet\r\nGarnet is a name that refers to a large group of rock-forming minerals. These minerals have a common crystal structure and general chemical composition X3Y2 (SiO4)3. In this general structure, X\" can be Ca, Mg, Fe2+ or Mn2+\" and Y\" can be Al, Fe3+, Mn3+, V3+ or Cr3+\".\r\n\r\nThese minerals are found all over the world in metamorphic, igneous and sedimentary rocks. Most near-surface garnets form when a sedimentary rock with a high aluminum content, such as shale, is subjected to enough pressure and heat to produce schist or gneiss. Garnet is also found in contact metamorphic rocks, subsurface magma chambers, lava flows, deep-source volcanic eruptions, and soils and sediments formed by weathering and erosion of garnet-bearing rocks.\r\nMost people associate the word \"garnet\" with a red gemstone. However, they are often surprised to learn that garnet comes in many other colors and has many other uses. In the United States, the major industrial applications of garnet in 2012 were waterjet cutting (35%), abrasive blasting (30%), water treatment granules (20%), and abrasive powders (10%).\r\n\r\n### Uses of garnet\r\nGarnet has been used as a gemstone for thousands of years. In the last 150 years, this substance has had many uses as an industrial mineral. The chart below shows recent industrial uses of garnet in the United States. Garnet is also used as an indicator mineral in mineral exploration and geological evaluations.\r\n\r\n### Garnet as an industrial mineral\r\n**Garnet abrasives**\r\nThe first industrial use of garnet was as an abrasive. Garnet is a relatively hard mineral that ranges from 6 to 7.5 on the Mohs scale. This property allows it to be used as an effective abrasive in many industries. When eroded, this material breaks into angular pieces that create sharp edges used for cutting and sanding purposes. The small, uniformly sized grains are glued to the paper to produce the red sandpaper widely used in woodworking shops. Crushed garnets are sold in special sieve sizes and as abrasive granules and powders. There are important sources of industrial garnet for abrasives in the United States and New York.\r\n** Blue jet cutting **\r\nThe largest industrial use of garnet in the United States is in waterjet cutting. A machine known as a waterjet cutter produces a high-pressure water jet with entrained abrasive grains. When they are driven into a piece of metal, ceramic or stone, a cutting action can occur that produces very little dust and is done at a low cutting temperature. Waterjet cutting is also used in mining.\r\n**Abrasive Blast**\r\nGarnet granules are also used in abrasive blasting (commonly known as sandblasting) by Steph.
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