Explanatory notes
… other oxides (e.g., titanium oxide, chromium oxide) either deriving from the natural starting material (bauxites) or … of air and acids, and is very hard. It is used, e.g., as an abrasive, in the manufacture of refractory conglomerates … metallurgy, as a filler for paints, in the manufacture of abrasives and synthetic precious or semi‑precious stones …
