7.5 - 8.0 on the Mohs scale.

Brazil

Dark blue, and very easily confused with tanzanite. These dark blue beryls are not aquamarine, but are light colored beryls treated with radiation, much in the same manner as blue topaz.

Dark blue beryl is always irradiated blue from pink or colorless beryl. The color can fade, avoid light or heat.

More information on gemstone enhancements.

Dark Blue Beryl is a member of the Beryl gemstone family.