There are several different varieties of Obsidian, all of which are forms of volcanic glass. Apache Tear Obsidian are black, roughly circular nuggets said to have been formed when the tears of the Apache People hit the dry earth as they were driven from their homelands. Mahogany Obsidian usually appears to be black, but when held to the light displays a dark, translucent brown color. Snowflake Obsidian is black glass scattered with white 'snowflake' speckles caused by volcanic ash settling on the molten glass before it cools.
Obsidian is sharp, easy to work with and fairly strong and has been used to make tools, weapons and ritual objects for thousands of years. Obsidian was an important stone in pre-columbian America. The Aztecs knew it as 'Iztli' or sometimes 'Teotetl' (Divine Stone). It was polished and crafted into special scrying mirrors that were sacred to the God Tezcatlipoca (Shining Mirror), who had one of his feet replaced with a round Obsidian mirror.
Obsidian is a shamanic stone that is said to help you gain understanding of the Web of Wyrd and the workings of destiny in your life. It is believed to lend strength to those who are weak and protect the gentle from abuse.
Because of its volcanic origins, Obsidian is strongly connected to the power of elemental Earth and Fire. It is an excellent stone for drawing Earth energy if you feel tired or depleted, and also for grounding excess energy if you feel anxious or 'spaced out'. Obsidian is said to be especially useful for people who live in urban areas or who have to endure an unpleasant atmosphere. It is believed to help shield you from unhealthy energetic noise, electromagnetic pollution and background electricity. A piece of Obsidian can also be used as a symbolic shield to protect yourself from negativity, curses or ill-wishing; an Obsidian mirror is ideal for this, as it can be used to 'reflect' unwanted energy away from you.