Blue Kyanite 5x10-20mm Top Drill Teeth - 15-16 Inch Agate this semi-precious variety of quartz

this semi-precious variety of quartz is found in many locations around the world

Quartz has been highly valued by virtually every civilization throughout history

Citrine is a transparent Quartz

and this phenomenon is thought to be due to impurities of yttrium or organic matter within the crystal lattice

Blue Kyanite 5x10-20mm Top Drill Teeth - 15-16 Inch Agate this semi-precious variety of quartzKyanite 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