Jasper is an opaque variety of chalcedony, which is a microcrystalline variety of the mineral Quartz. Opaque means that neither light nor images pass through. Microcrystalline quartz in its pure form is semitransparent. When a small amount of impurities or foreign materials are added to microcrystalline quartz, the color changes and its ability to transmit light decreases. Jasper contains enough impurities and foreign material to make it opaque.
It often contains an abundance of impurities, and therefore some regard it as a rock instead of a mineral. Jasper is usually associated with brown, yellow, or reddish colors, but may be used to describe other opaque colors of Chalcedony such as dark or mottled green and orange. Some forms of Jasper are banded, and these banded Jaspers may appear similar to Agate, but unlike Agate they are opaque. When Jasper is dull and lacking interesting colors or patterns, it is not Jasper but rather Chert.
Jasper is an opaque rock of virtually any color stemming from the mineral content of the original sediments or ash. Patterns arise during the consolidation process forming flow and depositional patterns in the original silica rich sediment or volcanic ash. Hydrothermal circulation is generally thought to be required in the formation of jasper. The classification and naming of jasper varieties are attributed to various well-defined materials includes the geographic locality where it is found, sometimes quite restricted such as "Bruneau" (a canyon) and "Lahontan" (a lake), rivers and even individual mountains; many are fanciful, such as "forest fire" or "rainbow", while others are descriptive, such as "autumn" or "porcelain". A few are designated by the place of origin such as a brown Egyptian or red African jaspers.
Picture jaspers exhibit combinations of patterns such as banding from flow or depositional patterns, dendritic or color variations resulting in what appear to be scenes or images on a cut section. Diffusion from a center produces a distinctive orbicular appearance, i.e., leopard skin jasper, or linear banding from a fracture as seen in leisegang jasper. Healed, fragmented rock produces brecciated (broken) jasper.
While "picture jaspers" can be found all over the world, specific colors or patterns are unique to the geographic region from which they originate. For example Oregon’s Deschutes or Biggs jasper and Idaho's Bruneau jasper from the Bruneau River canyon are particularly fine examples. Other examples can be seen at Llanddwyn Island in Wales. A remarkable, pale, blue-green jasper, with patterns somewhat resembling those of malachite, occurs in a deposit at Ettutkan Mountain, Russia.
Kambaba Jasper Rough from Madagascar$96.80 Add to cart
Mushroom Jasper Rough from Arizona$41.69 Add to cart
Mushroom Jasper Rough from Arizona$69.52 Add to cart
Polished Deschutes Jasper from Elkins Gem Stones$179.00 Add to cart
Wild Horse Canyon Jasper Rough from Oregon$29.60 Add to cart
Wild Horse Canyon Jasper Rough from Oregon$10.85 Add to cart
Item # 47DESCJAS06200554
End Cut Deschutes Jasper from Elkins Gem Stones
Here's an excellent end cut, NOT polished, specimen of Deschutes Jasper that we obtained from Wally Marks of the Highway 50&95 rock shop in 1997. He obtained this from Hoot Elkins daughter Judy at Elkins Gem Stones in Prineville, Oregon in 1995. This piece was an end cut of a specimen Wally was working on in his workshop. For those of you who do not know who Hoot Elkins was, the discovery of this picturesque Jasper is attributed to him sometime in the 1960's. (Hoot died in 1994) This is a true classic specimen from a classic locale! Elkins Gem Stones closed in 2012
This specimen weighs 8.6 oz or 0.54 lbs (245g) and measures 5 x 3.2 x 0.25 to 1 inch (127 x 83 x 6.38 to 25mm)
Item # 53PORCJAS06204312
Porcelain Jasper Rough from Mexico
Here's an amazing old stock specimen of Porcelain Jasper from Mexico. We procured this in 2008 from a Mexican mineral dealer in Quartzsite, Arizona. It has amazing artistic shapes and colors. This specimen should make excellent slabs and cabochons.
This specimen weighs 38.5 oz or 2.4 lbs (1.09kg) and measures 6.1 x 4.4 x 2.7 inches (15.5 x 11.3 x 7cm)
Item # 56RFJAS06205234
Rain Forest Jasper from Australia
This stone is actually a rhyolite and not a jasper. However, because everyone refers to it as Rainforest Jasper, we will continue doing that here as well. Rainforest Jasper is the green form of Rhyolite and comes from Western Australia. It has greens, browns, and yellows that are reminiscent of the darkness of a rainforest, with its filtered light through green leaves and the brown forest floor.
Rainforest Jasper is a kind of Rhyolitic lava that can be found in volcanic areas. During the solidification process, gas bubbles are trapped inside and are filled by siliceous material, such as Quartz Crystals, Jaspers, and other minerals. It’s common to see quartz patches in the stone. And depending where they originated from, Rainforest Jasper can also contain Nepholite and Feldspar. Rainforest Jasper is also known as Australian Rainforest Jasper, Rainforest Rhyolite, Spherulitic Rhyolite, Agatised Rhyolite, and Green Rhyolite.
This specimen has a cut and polished face. It has natural fractures as is common with this material.
This specimen weighs 51.6 oz or 3.2 lbs (1.46kg) and measures 6.1 x 3.7 x 3.4 inches (15.7 x 9.5 x 8.7cm)