Kyanite
Kyanite is a blue to blue-green aluminum silicate that forms bladed, fibrous crystals. Its hardness varies with direction: 4.5 along the crystal and 6.5 to 7 across it on the Mohs scale. It is less suited to jewelry.
Kyanite is a blue to blue-green aluminum silicate that forms bladed, fibrous crystals. Its hardness varies with direction: 4.5 along the crystal and 6.5 to 7 across it on the Mohs scale. It is less suited to jewelry.