Ethically Sourced
&
Expertly Curated
At Centennial Gems, we source minerals the right way - directly from miners, claims, and long standing relationships around the world.
Each specimen is evaluated by hand for quality, locality, and authenticity, ensuring every piece offered is something we would keep in our own collection.
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Featured Items
Okorusu Mine, Otjiwarongo District, Otjozondjupa Region, Namibia
5” x 4” x 1/2”
306.5 grams
The mine is famous for outstanding blue and green fluorite crystals, often with phantoms. The mine management allows a specimen miner (Peter Eysselein) to extract fluorite specimens to be sold on the international market (Brandstetter, 2011). The first specimen mining contract was granted to Christopher L. Johnston, Johnston Namibia CC in 2001. Johnston Namibia CC mined specimens until late 2003. Prior to Mr. Johnston and Mr. Eysselein mining specimens, Okorusu Fluorspar (Pty) Ltd informally collected and offered specimens for sale, with proceeds being used for community development.
The Early-Cretaceous alkaline rocks/sövite complex intruded Late Precambrian Damara series (quartzites, marbles, and biotite schists). The metasedimentary rocks have been fenitized in the vicinity of the intrusion. Fluorite also replaces host-rocks (marbles and biotite schists).
REE-bearing minerals occur in beforsitic carbonatite dikes and carbonate-fluorite-bearing metasomatites. Their HREE content is significant.
Closed in 2014 due to increased stripping ratio and beneficiation problems.
Boekenhouthoek, Mkobola, Thembisile Hani Local Municipality, Nkangala District Municipality, Mpumalanga, South Africa
3 1/4” x 2 1/4” x 1 1/2”
127.6 grams
This is the area where the well-known among mineral collectors South African "cactus" or "spirit" quartz comes from. Amethyst is the most widespread color variety, however, it also occurs in all sort of other colors as well (white, gray, mauve, reddish-purple, brown, yellow).
According to Cairncross (2023), the first specimen appeared sometime in 1986 when a collector from the Pretoria Gem and Mineral Club offered some deep purple amethyst specimens for sale. At the time, the locality was very vaguely given as "Magaliesberg" (some old labels may still list this name as the locality) which is now known not to be the case.
The quartz specimens are found in the Bushveld Complex rocks approximately 70 km northeast of Pretoria. The Bushveld Complex is a world famous polymetallic igneous complex, most well-known for its platinum and chrome deposits, which are the largest in the world. These are contained in ultramafic and mafic rocks that form the lower portions of the complex. However, the upper parts of the Bushveld Complex are composed of granites and felsic rocks that are subdivided into three unit from oldest to youngest, the volcanic Rooiberg Group, the Rashoop Granophyre Suite and finally the Lebowa Granite Suite which intrudes into both of the above. The granophyre of the Rashoop Granophyre Suite is the host rock to the quartz veins and quartz / amethyst crystals at Boekenhouthoek and Mathys Zyn Loop.
Popular
Diamantina, Jequitinhonha valley, Minas Gerais, Southeast Region, Brazil
4 1/2” x 2 1/2” x 1 1/2”
167.4 grams