Iolite
Natural stone
A violet-blue stone that shifts colour as you turn it. Fairly hard, but with a cleavage, so protect it from knocks.
Hardness (Mohs): 7–7.5
Natural stone
A violet-blue stone that shifts colour as you turn it. Fairly hard, but with a cleavage, so protect it from knocks.
Hardness (Mohs): 7–7.5