Kyanite
Kyanite was discovered by Werner in 1790. Kyanite is an aluminum silicate, the chemical formula is Al2SiO5. The name comes from the Greek kýanos - blue. It is found in metamorphic rocks such as gneiss, eclogite, granulite, amphibolite, rarely in pegmatites, but also in sediments. It is usually blue or blue-green. But it can also be green, colorless and rarely yellow. Kyanite has an interesting property, namely that its crystals have different hardnesses in different directions. More info
Kyanite was discovered by Werner in 1790. Kyanite is an aluminum silicate, the chemical formula is Al2SiO5. The name comes from the Greek kýanos - blue. It is found in metamorphic rocks such as gneiss, eclogite, granulite, amphibolite, rarely in pegmatites, but also in sediments. It is usually blue or blue-green. But it can also be green, colorless and rarely yellow. Kyanite has an interesting property, namely that its crystals have different hardnesses in different directions.