Bill Tindall, E.Tn.
Dana lists no known mineral of composition- Cr2O3. From this fact it can be concluded that no natural source of chromium oxide was historically used as an abrasive.

It is easy to make "chromium oxide pigment" which is in fact a hydrated chromium oxide. Wrong crystal structure for the abrasive material. I don't know how the abrasive is made, but my guess would be by firing the pigment. As soon as it was discovered that chromium oxide could assume the crystal structure of corundum it would have been obvious to try it as an abrasive, if not before. I have no idea when this discovery happed, but likely historically relative to submicron alumina.

While crushing aluminum oxide to form an abrasive began centuries ago by crushing Corundum, and later synthetic aluminum oxide, the sub micron abrasive "alumina" is derived from another process. I doubt the fundamental knowledge to develop this process was known before about 1950's.