Black Obsidian

Chakra: Base
Astrological Sign: Sagittarius
Element: Earth

a pure glossy black colour, Obsidian is a fire stone, born of the volcano.
Used to create tools and weapons by many primitive people, it lets us slice to the core of a matter and to release and ground negativity. It is a powerful stone of protection. and grounds the root chakra.

Obsidian is considered extremely protective and said to allow no negative energy or negative spirit to enter. In the Middle Ages it was thought to drive out demons. It provides protection from negative spirits. 

Obsidian can be polished to a shiny mirror surface. Because of this shiny, mirror surface, Obsidian is attributed with the ability to reflect back to us our true selves. It reveals to us our flaws in no uncertain terms. Because of this property, obsidian is said to remove emotional blocks. Said to be a vision stone for use in vision quests and prophetic dreaming. 

Obsidian is a gemstone of the 1st Chakra. It provides protection, grounding and protection from negative self-image, especially with respect to our physical appearance. Extremely helpful in times of grief. Obsidian was given as a remedy for snake poison. 
also Useful to combat depression.