This is the tumbled and polished version of Yellow Obsidian. When you order this item, you will receive a hand-picked specimen from our stock of inventory. Yellow Obsidian can be used for your Solar Plexus Chakra and is really good for breath work. Though Black Obsidian is an Earth-made, semi-precious gem consisting of volcanic glass, most colored obsidians are man-made. They are made by introducing impurities to glass to give them a variety of colors.