Raw obsidian is a naturally occurring volcanic glass whose value is highly variable, depending on specific geological and market factors. This material forms when silica-rich felsic lava is rapidly cooled after a volcanic eruption, preventing the formation of crystalline structures. The price of an individual piece is not standardized like a commodity; instead, it depends entirely on its type, quality, and intended use.
Identifying Raw Obsidian
Raw obsidian is an amorphous substance, meaning it lacks the organized internal structure of true minerals. Its defining feature is a glassy, highly lustrous surface and a characteristic conchoidal fracture pattern, which produces sharp, curved, shell-like breaks. The most common form is deep black obsidian, which is typically opaque but can appear translucent when sliced thin. This material has a hardness of 5 to 6 on the Mohs scale, making it relatively soft and easily worked by lapidary artists.
While common black obsidian is widespread, the presence of various mineral inclusions and microscopic water bubbles creates more desirable types. Snowflake obsidian features white, radial clusters of cristobalite crystals that resemble snowflakes. Mahogany obsidian contains streaks of hematite or iron oxide, giving it reddish-brown coloration. Varieties that exhibit a metallic or iridescent sheen, such as Gold Sheen, Silver Sheen, or Rainbow obsidian, are particularly valued for their optical properties.
Key Factors That Influence Pricing
The market value of raw obsidian is based on several qualitative characteristics. The rarity of the optical effect is a primary determinant; common black obsidian is far less valuable than the spectacular Rainbow or Gold Sheen varieties. True Rainbow obsidian, which displays brilliant, multicolored iridescence due to layers of microscopic gas bubbles, commands a considerable premium. Purity also plays a substantial role, as pieces with minimal internal bubbles, cracks, or inclusions are preferred for carving and gem cutting.
Size and overall form are another major consideration, especially for artists looking for carving material. Large, intact, and structurally sound chunks, particularly those exceeding five pounds, are priced higher per unit of weight than small fragments or gravel. Pieces sourced from geographically significant deposits, like those in Glass Buttes, Oregon, or certain Mexican localities, can also fetch premium prices due to their known quality and origin. The quality of the sheen or color must be strong and visible, as faint or patchy effects diminish the piece’s desirability.
Establishing Market Value and Price Ranges
The price of raw obsidian varies dramatically depending on whether it is sold in bulk for industrial or lapidary use or as a high-grade collector specimen. Common black obsidian, often sold in large quantities, is the most affordable type. Wholesale and bulk retail prices range from $2.27 to $8.00 per pound, or $5 to $10 per kilogram. This bulk material is generally intended for rock tumbling, landscaping, or basic flint knapping, where overall volume is prioritized over a consistent internal structure.
The value escalates sharply for specialty varieties, which are often sold individually at a much higher rate. Raw Rainbow obsidian rough, even in bulk quantities for lapidary work, can sell for $5 to $13 per pound, or $20 to $50 per kilogram, depending on the strength of the color bands. The rarest and most intense types, such as high-quality Fire obsidian, can exceed $100 per kilogram for rough material due to its intense, flash-like color play.
Pricing also depends heavily on the market context. A buyer purchasing directly from a mine operator or wholesaler will pay significantly less than a retail customer at a rock show or online shop. A small, high-quality piece of rough Gold Sheen or Silver Sheen obsidian, sold as an individual display specimen, can easily retail for a price equivalent to $50 to $100 per kilogram. The overall worth of any raw piece is ultimately determined by the balance between its inherent geological beauty and the current demand from collectors and craftspeople.