Color: black or dark grey.
Specific gravity: 3.5 to 3.8.
Hardness: 6 to 9, depending on the mixture.
Use: abrasive powder.
MineralogyEmery, or corundite, is a dark granular rock.
Industrial emery may contain a variety of other minerals and synthetic compounds such as magnesia, mullite, and silica.
Content:Corundum, aluminium oxide.
Hercynite, iron-bearing spinels.
Magnetite, iron-bearing spinels
Rutile, titania, iron-bearing spinels.