Pietersite – Tempest in a Stone
Pietersite is a beautiful stone: rare, distinctive, and unique - no two are alike. It is an ideal gemstone for those who embrace their originality. This stunning stone, discovered in Namibia in 1962 was named in honor of its discoverer Sid Pieters, a prominent Namibian mineral dealer and explorer. Strikingly chaotic swirls of blue, gold, brown and black led to its other name - Tempest Stone.
Square cut Pietersite in sterling silver.
This piece has almost equal parts grey/blue and brown/gold making a striking ying-yang effect. Pendant & necklace available upon request.
Pietersite is often described as brecciated tiger’s-eye and hawk’s eye (blue variety of tigers eye) or a combination of the two. Despite many visual similarities to these gemstones, pietersite formed under very different, and specific geological conditions, making it significantly rarer.
Pietersite have the same “cat’s eye” effect as seen in tiger’s eye. This optical phenomenon, called chatoyancy, is like the luminous sheen seen on a spool of silk with a streak of reflected light perpendicular to the direction of the fibers. Chatoyancy in gemstones arises from fibrous minerals or inclusions within the stone. For a gemstone to display this phenomenon best it must be cut as a cabochon (rounded top with a flat base) rather than faceted, with the fibers oriented parallel to the base.
Pietetsite and silver pendant on colored aluminum chain.
In both tiger’s eye and pietersite, the effect is caused by long fibers of crocidolite (a type of amphibole mineral). In tiger’s eye, this mineral forms in flat seams parallel to the bedding planes and as seals along regional fractures in banded-iron formations. On the other hand, pietersite develops within dolostone cobbles that underwent fragmentary dissolution, brecciation, and silicification, followed by later fluid infiltration which formed the crocidolite. As is typical of dissolution breccias, the replacement of dolostone by silica was localized, which resulted in distinct patches of crocidolite with different fiber orientations. This produces the chaotic chatoyancy that differentiates pietersite from tiger’s-eye and results in a dizzying array of patterns that makes each stone unique.
A collection of Namibian pietersite, author’s own. Pieces are available for custom jewelry, contact Artisan Jewelry Creations.
The main source of pietersite was close to Kuruman, Namibia near the South African border. In 1966 pietersite was also discovered in China. However, the two source regions produce very different looking pietersite. Chinese pietersite tends to have more reds and browns with less chatoyancy than Namibian pietersite which contains lots of blue, grey, and gold. Chinese pietersite mines operated during the 1970's and 80's but subsequently closed due to flooding and have never reopened. In 1996 it was reported Namibian pietersite was becoming scarce because the mines were getting close to being depleted. Today, those mines are also closed.
There are currently no active pietersite mines anywhere in the world. However, the material from those mines is still available, although increasing in price as it becomes more and more scarce.