Natural Blue Obsidian (raw) Obsidian is a very special stone. It is not a true mineral. It is actually a volcanic glass that forms when molten lava cools too rapidly to crystallize. It consists mostly of Silicon Dioxide.
Tanzanite: This mineral stimulates the throat, the third-eye, and the crown chakras. It brings together all aspects of both communication and psychic power. Astrological signs of Sagittarius, Gemini and Libra.