Assertion: alexandrite's color | /r/HasSubevent | emerald
Facets:
Source sentences:
text: Pure beryl is colorless and only gains its bright hues from impurities in the rock: chromium and vanadium give beryl a green color resulting in an emerald; iron provides a blue or yellow tint creating aquamarine and golden beryl; and manganese adds the deep-red color to create red beryl.