Black obsidian is a glass-like rock that forms from volcanic lava cooling quickly.

 In feng shui, the color black is connected to the water element. Water represents wisdom, depth, and fluidity. If these are qualities you’d like to bring into your life, it may be helpful for you to work with black stones such as black obsidian. Water is also connected to career and social network. You might want to bring in more water element through the color black if you’d like to enhance these areas of your life. 

One of the most popular uses of black obsidian is to create a shield of protection to ward off negative or harmful energies. Wearing black obsidian or carrying it with you can help to absorb negativity that you may encounter.