Obsidian is a natural volcanic glass formed when molten lava cools so rapidly that mineral crystals cannot fully develop. This process results in a smooth, glossy material with a characteristic conchoidal fracture that produces extremely sharp edges. While typically jet-black, mineral inclusions can create a spectrum of colors and sheens, making it highly prized by collectors. Historically, ancient cultures used obsidian for crafting tools, weapons, and ceremonial objects, and it remains popular today for jewelry and lapidary work.
Collecting Obsidian in Natural Settings
Collecting obsidian in its natural state is tied to areas of recent volcanic activity, primarily concentrated across the Western United States. States like Oregon, California, Nevada, Arizona, and New Mexico hold extensive deposits due to their history of explosive volcanism. A significant collecting site is Glass Butte in central Oregon, an expansive area on Bureau of Land Management (BLM) land known for producing varieties like mahogany, rainbow, and gold sheen obsidian.
In California, sites such as the Warner Mountains and areas within the Modoc National Forest are popular destinations for rockhounds seeking specific types like rainbow and pink obsidian. Searching for pieces often involves exploring the margins of rhyolitic lava flows. Collectors typically use simple hand tools like a small shovel, hammer, pick, or pry bar to expose buried material.
Safety is paramount because obsidian edges are exceptionally sharp, often rivaling a surgical scalpel. Wearing heavy-duty gloves and eye protection is necessary to prevent injury from flying shards or accidental cuts. The best time for collecting is typically spring through fall, as winter snow and ice make access and surface visibility difficult in mountainous regions.
Legal and Ethical Rules for Collection
Collecting obsidian requires understanding land ownership and associated regulations. Most federal public lands managed by the Bureau of Land Management (BLM) and the U.S. Forest Service (USFS) permit non-commercial collection. Non-commercial collecting means the material is for personal use, hobby, or display and cannot be sold for financial gain.
The BLM generally allows rockhounding without a permit, typically limiting the amount to 25 pounds per day or 250 pounds per calendar year. The USFS may require a free permit for collecting, particularly if the activity involves surface disturbance. Collecting is strictly prohibited within National Parks or National Monuments, where a “take nothing but pictures” rule is enforced.
Collectors must verify land status and never trespass on private property without permission. Ethical rockhounding demands minimal impact: collectors should only use hand tools, avoid significant excavation, and leave the environment undisturbed. Disturbing or collecting archaeological artifacts, such as ancient obsidian tools, is illegal on all federal lands and can result in severe penalties.
Acquiring Obsidian Commercially
Commercial options exist for those who prefer to acquire obsidian without field collecting, offering pieces from raw chunks to finished carvings. Online marketplaces and specialized rock and mineral dealers provide a vast selection, sourcing material from major deposits in the U.S., Mexico, and other global locations.
Physical retail stores, such as metaphysical shops and local gem supply stores, allow buyers to inspect the piece directly before purchasing. Gem and mineral shows are another avenue to find unique specimens and negotiate pricing with dealers.
Pricing varies dramatically based on the obsidian’s form and rarity. Common raw black obsidian can be purchased in bulk for a relatively low cost, typically $5 to $30 per pound for unprocessed material. Rare varieties, such as polished Rainbow or Fire Obsidian, command significantly higher prices, sometimes priced by the ounce or carat for gem-quality cuts. Finished items like jewelry or carved sculptures are priced higher due to the labor and skill involved in cutting and polishing.
Identifying High-Quality Obsidian
Identifying high-quality obsidian involves looking for specific visual characteristics and unique inclusions that define its variety. While pure black obsidian is common, several other types are highly sought after for their distinct appearance.
Rainbow obsidian is prized for its iridescent, multi-hued sheen caused by microscopic inclusions of magnetite nanoparticles that reflect light in thin layers. Sheen obsidian, including gold and silver varieties, exhibits a metallic luster created by trapped gas bubbles aligning as the lava cools. Snowflake obsidian is recognizable by white, cotton-like patches of cristobalite—a form of silica—embedded within the dark glass. Mahogany obsidian features reddish-brown streaks caused by the inclusion of hematite or iron oxides.
In assessing a specimen, collectors look for a deep, saturated base color and a high-quality vitreous (glassy) luster. Desirable pieces have minimal internal fractures or cracks, as obsidian is naturally brittle. For iridescent varieties, a pronounced “play of color” visible from multiple angles indicates a top-tier specimen.