Assertion: zircon | /r/HasProperty | found as mineral owing
Facets:
value: occasionally
type: DEGREE
Source sentences:
text: Zircon is rare within mafic rocks and very rare within ultramafic rocks aside from a group of ultrapotassic intrusive rocks such as kimberlites, carbonatites, and lamprophyre, where zircon can occasionally be found as a trace mineral owing to the unusual magma genesis of these rocks.