Assertion: chrysoberyl | /r/MadeOf | ferric and chromic oxides
Facets:
value: in place of alumina
type: LOCATION
value: usually
type: TEMPORAL
Source sentences:
text: It usually contains some ferric and chromic oxides in place of alumina, and ferrous oxide in place of beryllia, and it is to these accessory constituents that its tints are due.