It combines with erythrite, forming another tannoid, erythrine.    From Wordnik.com.  [Synthetic Tannins] Reference

Cobalt produces the violet-red color in erythrite, (cobalt arsenic sulfide).    From Wordnik.com.  [Color + Design Blog by COLOURlovers / Feed] Reference

Under weathering conditions these minerals oxidize readily to form asbolite, a mixture of cobalt and manganese oxides, and the pink arsenate, erythrite or "cobalt bloom.".    From Wordnik.com.  [The Economic Aspect of Geology] Reference

A couple examples of these ores are erythrite.    From Wordnik.com.  [CreationWiki - Recent changes [en]] Reference