Emery (rock)
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Emery, or corundite, is a dark granular rock used to make an abrasive powder. The rock largely consists of corundum, mixed with other minerals. Industrial emery may contain a variety of other minerals
Emery mine on Naxos Island
Corundite from the Naxos emery deposits. The corundum is blue, or sapphire. Wet slab, 10 cm (3.9 in) wide.
Nail file
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A nail file is a tool that can be used to gently grind down and shape the edges of nails. They are often used in manicures and pedicures after the nail has been trimmed using appropriate nail clippers
Emery (rock)
…but the hardness of others such as magnetite is near 6. Crushed or naturally eroded emery (known as black sand) is used as an abrasive—for example, on emery boards and emery cloth. It is also used as a traction enhancer in asphalt and tarmac mixtures. A small quantity of emery is used in coated abrasive products…
Nail files