Black Obsidian, as you already know, is not a crystal. It is, however, an igneous stone. Igneous stones and crystals are formed from cooled volcanic lava, either from active volcanos or from lava in the center of the earth’s crust. Sometimes, volcanic lava cools quickly, which does not allow crystals to form. When this happens, a smooth, volcanic glass-like rock is formed. This type of rock is called a mineraloid. Black Obsidian is a mineraloid with rich, deep color and smooth surface that is somewhat mirror-like. The most common colors of Obsidian stones are black. However, Obsidian can also be found in greens, tans, and browns. Rare colors of Obsidian can be found in blues, reds, yellows, and oranges, and even two colors in a swirled-together, marble-like pattern. Obsidian is not a rare stone. It is found all over the world, in both North and South America, and in many parts of Asia, including eastern Russia and Japan. Most of the Black Obsidian used in jewelry is mined in the United States. However, Obsidian is not found east of the Mississippi River due to a lack of volcanic activity.