Rhodochrosite

Rhodochrosite forms in cavities of metamorphic rock and is associated with silver. Once known as Rosa del Inca, legends say, rhodochrosite was found in abandoned Incan silver mines from the 13th century. Ever since, rhodochrosite has become the national gemstone of Argentina. Current development of the Capillitas Mining District has on the one hand allowed professional travelers and mineral collectors access to the stalactite caverns. On the other, this mineral has a tradition as a byproduct of silver mining and caverns have been destroyed by official pursuit of development. For comparison, high quality crystals of rhodochrosite were also found by a team of prospectors but in the early-1990s in the United States at a defunct Colorado silver mine. The "Alma King" being the largest known specimen of pure manganese carbonate crystal is on display at Denver’s Museum of Nature and Science. The Alma King, a rhombohedral crystal measuring-in at 14 cm by 16.5 cm, was found at Alma, Colorado at the Sweet Home Mine. Iron, magnesium, and calcium normally discolor the cherry-red crystals as naturally occurring inclusions found at the mine. The pink color of rhodochrosite is due to trace amounts of these inclusions. The attractive pink color is said to make wonderful carvings for tourists; moreover, the miners at Capillitas, Argentina can remove rhodochrosite from the rock and cut slabs of the mineral into cabochons -- some on sale in Buenos Ares. A typical cabochon is an elongated oval with fleshy pink colored crystals sandwiched between marbled bands of off-white calcite layers. A cross section from a cavern can be unnerving because of the fleshy color. Other cabochons such as those from Japan do not display banding and focus on the rosy, red crystals instead. “Slabbed” rhodochrosite may appear to the eye like cut & polished agate. Since its a semi-precious gemstone like agate, rhodochrosite increases in value as more expensive gems become scarcer. The softness of this mineral makes it best suited for displays rather than for jewelry that may be better suited for agate. Local markets have turned this gemstone into a specialty item contrasted against expectation. Entire stores appear dedicated to it. Examples produced by the hydrothermal process known as “vein rhodochrosite” appear to flourish in a wide range of locations, a lot of knowledge can be obtained by inquiry about individual mines; yet the concentric bands appear to be missing. When rhodochrosite's found inside a cavity such as those in Argentina, deposits form in layers and form stalactites on the roof or stalagmites on the floor. These specimens found in Argentina and have a characteristic pink banding. The pink banding of rhodochrosite is a feature of cutting the stalactite or stalagmite in cross section. Discovered in Sacaramb, Romainia, during the 19th century, the name was derived from the Greek rhodon meaning "rose red" and chros meaning "color". The name extending from Greek adds to the popularity of this mineral. Few studies have been done to uncover the mystery of crystalline rhodochrosite (mindat.org), however, crystals were found at the Sweet Home Mine at Alma, Colorado, as mentioned earlier. The Sweet Home Mine was opened as a silver ore mine during the 1870s and remained open until the 1960s. In 1992, the mine reopened to mineral prospectors with considerable success making manganese carbonate the official mineral of Colorado. Some sources say, mineral prospecting at the mine was popular during the late 19th century; however, the mine was in operation at that time. Rhodochrosite is composed of manganese carbonate so it's a source of manganese. Yet, manganese carbonate can interfere with the amalgamation of silver ore. Therefore, the mineral is discarded. Only a handful of places were rhodochrosite has lapidary and mineral uses such as South Africa, Russia, Japan, Gabon, and Mexico. The lapidary use of high-quality banded manganese carbonate is for decorative stones. Since rhodochrosite is difficult to cut due to its perfect cleavage, faceted gems of this stone are a rarity.