Obsidian

Obsidian's base matrix is earth, while secondary  it has fire.  Obsidian is "natural glass". Obsidian 's main component is quartz, but it has no crystal structure.  Obsidian is formed when lava cools, and thus gets part of it's fire.  Obsidian stimulates growth physically, emotionally, and intellectually.   Obsidian provides vitality, and strength.  Obsidian's good for clearing blockages, and transmutation of energies.  Obsidian is good for healing, one of the best grounding stones I've ever encountered.  Obsidian cConnects you right up to the earth, and your energy construct alignment.

Black vibrates to 1

Mahogany  vibrates to 4