who used it extensively in their jewelry
The color of Smoky Quartz is due to natural irradiation and traces of aluminum within the crystal lattice of the stone
Obsidian is produced when lava erupts from a volcano and cools rapidly with minimal crystal growth
It's actually a pink variety of Beryl -- the family of gemstones that also includes Aquamarine
Blue Kyanite 10mm Round - 15-16 Inch R1851 who used it extensively inKyanite often occurs as long, bladed, striated crystals, transparent or translucent with a pearly luster. An aluminum silicate mineral, it may appear in white, pink, yellow, orange, green, blue, gray and black. In addition to its value as a gemstone, Kyanite is also extremely useful in industrial applications due to its high heat resistance. It is often used in kiln furniture and foundry molds, as well as for brake shoes, grinding wheels and cutting