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  • A remarkable rhodochrosite specimen featuring sharp scalenohedral crystals with deep cherry-red to orange coloration and exceptional gemmy transparency. The 7 cm specimen from Gabon's scarce Moanda Mine displays brilliant surface luster, complete coverage, and represents a superior example from this historic African locality.
  • A remarkable rhodochrosite specimen featuring sharp scalenohedral crystals with deep cherry-red to orange coloration and exceptional gemmy transparency. The 7 cm specimen from Gabon's scarce Moanda Mine displays brilliant surface luster, complete coverage, and represents a superior example from this historic African locality.
  • A remarkable rhodochrosite specimen featuring sharp scalenohedral crystals with deep cherry-red to orange coloration and exceptional gemmy transparency. The 7 cm specimen from Gabon's scarce Moanda Mine displays brilliant surface luster, complete coverage, and represents a superior example from this historic African locality.
  • A remarkable rhodochrosite specimen featuring sharp scalenohedral crystals with deep cherry-red to orange coloration and exceptional gemmy transparency. The 7 cm specimen from Gabon's scarce Moanda Mine displays brilliant surface luster, complete coverage, and represents a superior example from this historic African locality.
  • A remarkable rhodochrosite specimen featuring sharp scalenohedral crystals with deep cherry-red to orange coloration and exceptional gemmy transparency. The 7 cm specimen from Gabon's scarce Moanda Mine displays brilliant surface luster, complete coverage, and represents a superior example from this historic African locality.
  • A remarkable rhodochrosite specimen featuring sharp scalenohedral crystals with deep cherry-red to orange coloration and exceptional gemmy transparency. The 7 cm specimen from Gabon's scarce Moanda Mine displays brilliant surface luster, complete coverage, and represents a superior example from this historic African locality.
  • A remarkable rhodochrosite specimen featuring sharp scalenohedral crystals with deep cherry-red to orange coloration and exceptional gemmy transparency. The 7 cm specimen from Gabon's scarce Moanda Mine displays brilliant surface luster, complete coverage, and represents a superior example from this historic African locality.
  • A remarkable rhodochrosite specimen featuring sharp scalenohedral crystals with deep cherry-red to orange coloration and exceptional gemmy transparency. The 7 cm specimen from Gabon's scarce Moanda Mine displays brilliant surface luster, complete coverage, and represents a superior example from this historic African locality.

RHODOCHROSITE

Moanda Mine, Léboumbi-Leyou Department, Haut-Ogooué Province, Gabon
8.5 x 8.3 x 3.6 cm
$1,850.00
$1,850.00
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ABOUT THE SPECIMEN

Generous coating of sharp, cherry red to orange rhodochrosite scalenohedrons atop contrasting manganitic matrix. The crystals are gemmy with superb sparkling luster, giving fantastic reflections in even dim light. On the front side is a ridge in the matrix with great coverage of rhodos that pops out to the forefront. Backside also has plenty of quality crystals, so this piece is attractive from all angles. The Moanda Mine in Gabon is a long-lost locale for rhodochrosite, and a more seldom known one at that. Modern workings go purely after ore, with no quality specimens surviving the process. Not a lot of well-formed specimens were unearthed there at any period of time, with much of the rhodochrosite that formed in the deposit having weathered to manganite, making this piece an unusually excellent example for the mine. This is in excellent condition, and any contacting or chipping isn't worth noting with how hard it is to spot amongst the numerous perfect crystals.

 

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MORE INFO

Moanda is one of the world's largest and highest-grade manganese deposits, hosted in bedded Paleoproterozoic Francevillian Formation sediments atop five plateaus in southeastern Gabon, where early diagenetic processes involving organic matter drove manganese concentration as primary rhodochrosite - subsequently overprinted by weathering that converted most of the carbonate to manganite and other oxides. Rhodochrosite survived only in specific vuggy zones where weathering was incomplete, crystallizing as scalenohedral prisms to 9 mm in cavities within the dense black manganite matrix, the stark contrast between cherry-red to reddish-brown gemmy crystals and the surrounding black ore being the defining visual. A ScienceDirect study on lateritic manganese profiles confirmed that manganite at Moanda forms by direct replacement of rhodochrosite, which explains both the rarity of intact crystals and why even modest specimens carry scientific interest as survivors of that replacement process. The known specimen-producing windows date primarily to the 1960s through early 1980s, with no significant material documented since. The mine, operated by Compagnie Minière de l'Ogooué, continues producing industrial ore at high volume; rhodochrosite simply no longer survives in the portions now being worked, making all collector material genuinely old-stock with a fixed and diminishing supply.