Jasper is an opaque, impure variety of silica that can come in a wide range of colors. It is prized as an ornamental gemstone and has been used since antiquity for jewelry, carvings, and other decorative objects. But some colors of jasper are much rarer than others.
One of the rarest jasper colors is a vivid green variety known as Mookaite Jasper. It is found in just one location – along the Mooka Creek in Western Australia. Mookaite gets its distinctive green color from chlorite inclusions. It often has uniqueorbicular patterns and contrasts nicely with shades of red, yellow, black, and white. High quality mookaite is highly valued by lapidaries and collectors. Only small amounts are mined each year, as mookaite deposits are not abundant.
Another exceptionally rare jasper is Fossiliferous Jasper, sometimes called Bone Jasper. True fossiliferous jasper contains at least 30% replacements of organic materials by silica. It preserves cellular structures and fossils in incredible detail. The most prized fossiliferous jasper is found in Bruneau Canyon in Idaho. It formed from hot silica saturated waters permeating and replacing shells and plant matter in a volcanic ash deposit. This jasper displays vivid oranges, reds, yellows, and browns in abstract organic patterns. Mining fossiliferous jasper is extremely limited due to regulations protecting the fossil beds.
Ruby in Zoisite Jasper is also one of the rarest and most expensive forms of jasper. It displays opaque vibrant red ruby inclusions in contrast to the translucent grayish green zoisite matrix. The color combination is highly attractive. Ruby in zoisite jasper has only been found in Tanzania. The ruby inclusions are actually anythroite, a rare calcium, iron, manganese sorosilicate mineral belonging to the epidote group. Ruby in zoisite jasper is challenging to cut due to the hardness differences between the materials. But when expertly cut, it makes truly unique jewelry.
Meanwhile, Leopardskin Jasper is a rare silicified rhyolite found near Hot Springs, South Dakota. It formed from the stretching and twisting of bands of pink, green, and cream colored sediments. This gave it a distinctive orbicular appearance resembling a leopard's fur. Leopardskin jasper is no longer actively mined and existing supplies are quite limited.
The rarest jaspers are found in specific remote locations and geological contexts. Their distinctive colors and patterns, formed over eons, cannot be exactly replicated. Rarity adds value, but also means some of the most prized jasper varieties are becoming scarce. Collectors and jewelers should appreciate these rare jaspers when they uncover them. Their unique beauty is fleeting.
