Jasper is a common, opaque variety of microcrystalline quartz (a form of chalcedony) known for its dense texture and rich, varied coloration. The stone’s vibrant appearance results from fine mineral impurities, most often iron oxides, which become incorporated during its formation. This guide focuses on the specific characteristics that aid in identification, the methods for collecting it in the field, and the locations where the most sought-after varieties can be found.
Identifying Jasper
Jasper’s physical properties are key to identifying it in a natural setting. As a member of the quartz family, it exhibits a hardness of 6.5 to 7 on the Mohs scale, meaning it is durable and will scratch common glass. The stone is defined by its opacity; unlike translucent agates, a true jasper will block all light, even when held up to a strong source.
The stone’s unique microcrystalline structure gives a fresh break a distinct conchoidal fracture. When weathered or in a riverbed, jasper often develops a smooth, almost waxy luster that is noticeable even when the rock is dry. The presence of iron gives it a wide color palette, with reds, yellows, and browns being the most common hues, while deep greens and blues are found in specific, localized deposits.
The name of a jasper variety often describes its appearance or origin. Picture Jasper is characterized by patterns that resemble miniature landscapes in layers of brown, tan, and cream. Orbicular varieties, such as Ocean Jasper from Madagascar, are easily recognized by their spherical, eye-like patterns. Red Jasper gets its color from high concentrations of iron oxide, or hematite, resulting in a solid, deep crimson to brick-red stone.
Methods for Rockhounding Jasper
Jasper is commonly found in areas where its source rock has weathered and eroded, concentrating the stone in gravel deposits. Riverbeds, dry desert washes, and beach gravel bars are prime locations because the water action tumbles and polishes the pieces, making their color and waxy texture stand out. Searching immediately after a heavy rain often improves success, as the moisture washes away dust and intensifies the stone’s coloration, causing it to “pop” against lighter-colored rocks.
When searching a stream or wash, train your eye to quickly scan for the tell-tale waxy sheen and a solid, vibrant flash of color. Since jasper is relatively heavy, it tends to settle in areas where the water current slows, such as the inside bends of rivers or behind large obstacles. A simple squirt bottle is useful for wetting a potential find on-site to reveal its true color and pattern without having to carry it back to a water source.
Necessary equipment for field collecting includes a sturdy rock pick or geological hammer for breaking apart larger matrix rock or prying loose embedded pieces. Safety gear such as gloves and protective eyewear is recommended, especially when striking rock. For transporting finds, a canvas bag or a small, durable bucket is preferable to avoid tearing a backpack with sharp edges or overloading a standard bag.
Specific Collection Sites
The United States offers several well-known locations for collecting high-quality, named varieties of jasper, particularly in the western states. Oregon and Idaho are home to some of the most famous deposits of picture jasper, a type prized for its scenic, landscape-like patterns. Biggs Jasper, sourced near Biggs Junction, Oregon, is known for its intricate layering that often displays geological formations within the stone itself.
Bruneau Jasper originates from the rugged canyon walls near the Bruneau River in Idaho. This type is recognized for its orbicular patterns and rich, porcelain-like quality, though the original deposit areas are often difficult to access and may be subject to private claims or land management restrictions. In Arizona, the Cave Creek area is known for producing a deep, rich red jasper, where the stone is often found as float in washes and on hillsides rich with iron-stained volcanic rock.
Beyond North America, international sources provide unique jasper varieties. Madagascar is the primary source for Ocean Jasper, an orbicular stone with a striking array of colors and patterns. The island also yields Polychrome Jasper, a stone known for its earthy palette of reds, browns, and yellows. Before visiting any location, research local regulations, land ownership, and collecting limits, as many of the most famous sites are on private property or government-managed land that prohibits or restricts amateur collection.
Acquiring Jasper Commercially
For those unable to travel to a collection site or interested in acquiring specific, high-grade material, several commercial avenues exist for purchasing jasper. Rough jasper is widely available through online dealers who specialize in lapidary rough, often selling the stone by the pound in bulk quantities suitable for tumbling or slabbing. These sources often import unique international varieties, such as Desert Jasper or Imperial Jasper, directly from their country of origin.
These rough stones are sold in their natural, unpolished state, requiring the buyer to cut, grind, and polish them to reveal their full potential. Gem and mineral shows, held annually in many cities, provide a direct point of purchase from wholesalers and miners, allowing buyers to inspect the material in person before committing to a purchase. Local lapidary shops are another resource, offering both rough stone and finished products like cabochons, which are pre-cut and polished pieces ready for jewelry setting.