2023 Calendar: Tsumeb – The King of Mineral Localities, a 16-month calendar.
From the Preface:
Six hundred million years ago, the southern part of Africa was involved in a continental reassembly, driven by plate tectonics. In the process of forming the large continent Gondwana, two ancient continental land masses — the Congo and Kalahari cratons — collided. The cratons “sutured” during the Damaran orogeny, and the ensuing tectonic activity initiated deep-seated magmatic activity, deformation, and metamorphism that set the stage for mineral-laden fluids to percolate through ancient limestone and dolomite to form the backbone of the Otavi Mountainland.
Over the next half billion years, the Otavi Mountainland underwent numerous episodes of deformation, including folding, faulting, and most importantly the development of karst topography. The entire region is filled with polymetallic mineral deposits, which number north of 600 . Tsumeb, however, stands out both in size and mineral diversity. The Tsumeb deposit is a pipe-like structure in which the primary sulfide ores were concentrated. Meteoric waters percolated through the host limestone/dolomite and dissolved the carbonates, creating sinkholes and cavities, and laying the groundwork for a most unique mineral deposit.
The fluctuating water table altered the primary sulfide minerals and created at least three distinct oxide zones filled with the colorful secondary species that have made Tsumeb famous. Mineral specimens from these zones are represented in every major collection in the world, and no fewer than 489 different species, representing some nine percent of all defined minerals, have been identified from the locality. Seventy-two of those species were first identified at Tsumeb; an astonishing forty of them have not been found anywhere else in the world. And the deposit continues to surprise as fresh analyses of specimens long-ago mined increase the suite of minerals known from this important and storied locality.
And diversity is only part of the story: the extraordinary range of colors and exquisite beauty of Tsumeb’s minerals testify to the unique set of circumstances that gave rise to the deposit. There is common agreement among mineral collectors that Tsumeb produced the very finest examples of nearly 100 species. From the outrageous color and size of its sole type specimen of andyrobertsite (right) to the mine’s namesakes tsumebite and tsumcorite to its rainbow of calcites and smithsonites and its mind-blowing pseudomorphs, Tsumeb reigns as the “King of Mineral Localities.”
The calendar is published by Lithographie, LLC in cooperation with Denver Area Gem & Mineral Show, Fine Mineral Shows, LLD Productions, Inc., The Mineralogical Society of America, RMGM Promotions, and Tucson Gem and Mineral Society