Assertion: mineral's structure | /r/HasProperty | occupied by ion
Facets:
Source sentences:
text: Tourmaline Chemistry Tourmaline is a complex boron silicate mineral with a generalized chemical composition of: XY 3 Z 6 (T 6 O 18 )(BO 3 ) 3 V 3 W Letters in the formula above represent positions in the atomic structure of tourmaline that can be occupied by ions listed below.