Assertion: amethyst | /r/HasAspect | hardness
Facets:
Source sentences:
text: This is not a complete guide on how to spot a fake amethyst or man-made amethyst, which has the same crystal structure, hardness and specific gravity
text: The amethyst has its hardness (7), its moderate refraction and its weight in common with the other quartzes, but the crystal structure is different, and it is most unconventional.