Assertion: natural cryolite | /r/ObjectUse | used for this purpose
Facets:
Source sentences:
text: As natural cryolite is too rare to be used for this purpose, synthetic sodium aluminium fluoride is produced from the common mineral fluorite.
text: Now, as natural cryolite is too rare to be used for this purpose, synthetic sodium aluminium fluoride is produced from the common mineral fluorite.