Uchucchacua Mine, Oyon Prov., Lima Dept., Peru
7.6 cm tall x 12.7 cm wide
This is one of the finest known rhodochrosites from Uchucchacua, Peru. The other is in the collection of the Houston Museum (pictured in Masterpieces of the Mineral World, pg. 66). They are very different. When comparing this to other worldwide rhodochrosites it would be impossible to say where it fits. Colorado, N'Chwaning, and Peru (two very different localities: Uchucchacua and Huallapon Mine), to break this down to these 4 locations puts some measure of perspective, but it really means nothing. They are all so different, each amazing, they cannot be compared. Simply because they are all the same species does not mean they are comparables. It would not be much different then stating botryoidal smithsonite is the same as crystallized. Same species, but completely different appearance.
This rhodochrosite has unusually large elongated crystals. They are a unique combination of scalenohedrons and rhombohedrons. This gives the crystals a shape with large flat faces along the sides, as well as large clear terminal faces. This feature allows the deep red color to glow. The color is also unique. It shades from a deep dark wine red, almost burgundy, to various hues of orange, giving the crystals a bicolor effect. The rhodochrosite sits atop a black and clear/white matrix for a dramatic color contrast. The background is a slick and shiny black manganese oxide. Growing over the black matrix is a bed of bright and sparkling clear quartz crystals.
Several of the rhodochrosite crystals are of such high quality they possess the appearance of faceted gems with a ruby red glow. They are flawless, sharp, and with glass like luster. It is amongst the finest rhodochrosites in the world, and amongst the finest Peruvian minerals.