Sugilite Suglilite is composed of potassium lithium iron manganese aluminum silicate, with a hardness of 6 to 6.5 and a density of 2.76 to 2.80 and hexagonal crystals. It is named after a Japanese geologist, Ken-ichi Sugi who discovered it in 1944. It is found in Japan and Canada, but much of the world’ s [...]