Dumortierite
Hardness: 7-8,5 Color: blue, violet-blue, greenish-blue, pink, red, reddish brown Formula: Al7(Bo3)(Sio4)3O3 Crystal System: orthorhombic The dumortierite was named after the french paleontologist Dumortier. It was discovered in France in 1881, near the settlement Chaponost. It mostly issues in pegmatites, sometimes in metamorphic rocks in massive grainy, fibrous shapes, rarely in prismatic crystals. It occurs...