Encyclopedia
Emery
Emery consists of a dense rock formed from fine hard crystals of aluminum oxide mixed with iron oxide and particles of mica. It often occurs in the form of rock and is used as an abrasive powder after simple grinding. Ground emery is a brown powder sometimes containing shiny grains; a magnet attracts iron oxide particles
Source: "Explanations to the Commodity Nomenclature of Foreign Economic Activity of the Russian Federation (HSN RF)" (prepared by the Federal Customs Service of Russia) (volume 1, sections I - VI, groups 1 - 29)