Other than the moonstone, there are more minerals with the Moon being part of their name: the moonlight topaz. The topaz is a compound of aluminum, fluorine and silicon and has the hardness value of 8, on the Mohs scale of mineral hardness from 1 (= selenite) to 10 (= diamond). Which means it is a very hard mineral. Topazes exist worldwide, but most findings originate in Brazil. When conditions are favorable for the growth of this mineral, their weight can easily reach up to 220 lb and more. The biggest topaz that was ever found, was 3.3 ft long and weighed 2.5 tons (Mozambique, Africa).
Potassium, aluminium, silicon, oxygen and some other ingredients result in a mineral in a certain compound, which has received the name moonstone due to its whitish, shimmering glow. This stone has already been known in old cultures. The Romans viewed it as solidified rays of the Moon, the old Greek connected it to the moon goddess Selene.