The color of black obsidian is black.
The mohs hardness of black obsidian is 5.0 - 5.5.
The mohs hardness scale from 1 (the lowest hardness) to 10 (the highest hardness).
Black obsidian associates with sagittarius.
Black obsidian can work with root chakra.
Digestive system and digestive problems
Lack of grounding
Lack of masculinity