ABRASIVES

Listing description Emery  (or corundite) is a dark granular rock used to make abrasive powder. It largely consists of the mineral  corundum  ( aluminium oxide ), mixed with other species such as the iron-bearing  spinels ,  hercynite , and  magnetite , and also  rutile  ( titania ). Industrial emery may contain a variety of other minerals and synthetic compounds such as  magnesia ,  mullite , and  silica . Detailed description It is black or dark grey in colour, less dense than translucent-brown corundum with a  specific gravity  of between 3.5 and 3.8. Because it can be a mixture of minerals, no definite  Mohs hardness  can be assigned: the hardness of corundum is 9 and that of some spinel-group minerals is near 8, 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 an  emery bo...

Listing description EMERY  Man-made emery is a regular aluminum oxide containing a small amount of ferric oxide. This addition gives high durability. Emery is recommended for hand polishing of ferrous and nonferrous materials. Emery  (or corundite) is a dark granular rock used to make abrasive powder. It largely consists of the mineral  corundum  ( aluminium oxide ), mixed with other species such as the iron-bearing  spinels ,  hercynite , and  magnetite , and also  rutile  ( titania ). Industrial emery may contain a variety of other minerals and synthetic compounds such as  magnesia ,  mullite , and  silica . Detailed description It is black or dark grey in colour, less dense than translucent-brown corundum with a  specific gravity  of between 3.5 and 3.8. Because it can be a mixture of minerals, no definite  Mohs hardness  can be assigned: the hardness of corundum is 9 and that of some spinel-gro...