Obsidian

Weight is a decisive factor affecting the price of obsidian. The price of a tumbled stone around 2.5 cm across is usually $1-$5/piece.

The poor toughness of obsidian is attributed to its shell-like fracture pattern and the absence of a crystalline structure, which predisposes it to chipping and breaking upon impact.

Obsidian maintains integrity under most conditions but should avoid rapid temperature changes and harsh chemicals.

Obsidian is found in locations which have undergone rhyolitic eruptions. It can be found in Argentina, Armenia, Azerbaijan, Australia, Canada, Chile, Georgia, El Salvador, Greece, Guatemala, Iceland, Italy, Japan, Kenya, Mexico, New Zealand, Papua New Guinea, Peru, Scotland, The Canary Islands, Turkey and the United States. Obsidian flows which may be hiked on are found within the calderas of Newberry Volcano and Medicine Lake Volcano in the Cascade Range of western North America, and at Inyo Craters east of the Sierra Nevada in California. Yellowstone National Park has a mountainside containing obsidian located between Mammoth Hot Springs and the Norris Geyser Basin, and deposits can be found in many other western U.S. states including Arizona, Colorado, New Mexico, Texas, Utah, and Washington, Oregon and Idaho. Obsidian can also be found in the eastern U.S. states of Virginia, Pennsylvania and North Carolina. There are only four major deposit areas in the central Mediterranean: Lipari, Pantelleria, Palmarola and Monte Arci. Ancient sources in the Aegean were Milos and Gyali. Acıgöl town and the Göllü Dağ volcano were the most important sources in central Anatolia, one of the more important source areas in the prehistoric Near East.

Ancient civilizations used obsidian extensively in tool-making, as it can be cut into extremely sharp blades. Obsidian is also commonly used as a gemstone, or larger pieces may be carved as sculpture for decorative purposes.

Obsidian dates back to the stone age when it was used to carve spears and arrowheads. Ancient Mayan and Aztec civilizations long held the belief that the stone held magical powers and would allow them to communicate with the spiritual realm. Mayan prophets used it to foretell the future. It was often used to carve amulets and decorate gravesites.

Obsidian is found in locations which have undergone rhyolitic eruptions. It can be found in Argentina, Armenia, Azerbaijan, Australia, Canada, Chile, Georgia, El Salvador, Greece, Guatemala, Iceland, Italy, Japan, Kenya, Mexico, New Zealand, Papua New Guinea, Peru, Scotland, The Canary Islands, Turkey and the United States. Obsidian flows which may be hiked on are found within the calderas of Newberry Volcano and Medicine Lake Volcano in the Cascade Range of western North America, and at Inyo Craters east of the Sierra Nevada in California. Yellowstone National Park has a mountainside containing obsidian located between Mammoth Hot Springs and the Norris Geyser Basin, and deposits can be found in many other western U.S. states including Arizona, Colorado, New Mexico, Texas, Utah, and Washington, Oregon and Idaho. Obsidian can also be found in the eastern U.S. states of Virginia, Pennsylvania and North Carolina. There are only four major deposit areas in the central Mediterranean: Lipari, Pantelleria, Palmarola and Monte Arci. Ancient sources in the Aegean were Milos and Gyali. Acıgöl town and the Göllü Dağ volcano were the most important sources in central Anatolia, one of the more important source areas in the prehistoric Near East.

The translation into English of Natural History by Pliny the Elder of Rome includes a few sentences about a volcanic glass called obsidian (lapis obsidianus), discovered in Ethiopia by Obsidius, a Roman explorer.

Obsidian is considered a protection stone, that shields against negativity with truth-enhancing properties. It is said to bring clarity to the mind, drawing out mental stress and tension that sometimes leads to confusion. You can carry it with you to help ward off negative forces or keep the stone in your home, office, or anyplace you need protective energy.