Assertion: calcite's crystal | /r/HasAspect | uniaxial symmetry
Facets:
Source sentences:
text: Depending on the symmetry of a crystal structure (as determined by one of the 32 possible crystallographic point groups), crystals in that group may be forced to be isotropic (not birefringent), to have uniaxial symmetry, or neither in which case it is a biaxial crystal.