Assertion: tourmaline | /r/HasProperty | mineral
Facets:
Source sentences:
text: Tourmaline is a mineral that is complex in nature.
text: Tourmaline is its own mineral, and the presence of various trace elements such as aluminum or iron are what creates its different colored varieties.
text: Tourmaline is one of the few minerals in the world that occurs in natural biclor crystals, and this set features a lovely gem and crystal from Afghanistan, one of the most productive Tourmaline producing countries in history.
text: Tourmaline is a mineral because it has a characteristic crystalline form.
text: Tourmaline is a mineral represented with a chemical formula, NaX.sub.3 Al.sub.6 (BO.sub.3).sub.3 Si.sub.6 O.sub.18 (OH).sub.4.
text: Tourmaline is a mineral or gemstone that’s crushed up and layered on top of the plates.
text: Tourmaline is a gemstone or mineral that’s ground up and spread onto the surface of the iron.