Assertion: calcium carbonate | /r/AtLocation | chalk
Facets:
value: naturally
type: MANNER
Source sentences:
text: Calcium carbonate occurs naturally in chalk, marble and limestone.
text: Calcium carbonate occurs naturally in several mineral forms including the pure calcite, aragonite and vaterite minerals as well as the impure minerals-limestone, chalk, marble and travertine.
text: Calcium carbonate (CaCO3) is a mineral that occurs naturally in chalks, limestones and marbles.