Discover the Crown Jewel of the Rice Museum

Learn more about the Alma Rose Rhodochrosite

By Rice Museum of Rocks and Minerals

Photo by Jeff Scovil

Alma Rose Rhodochrosite, Photo by Jeff ScovilRice Museum of Rocks and Minerals

Zoom in

Its cluster of bright red rhodochrosite crystals is a beacon visible across a room. Get closer, and orange calcite and spiky quartz come into view. Look closer still and discover pale blue fluorite cubes scattered over the quartz, along with dark sulfur minerals below.

What is it? The Alma Rose's primary mineral is rhodochrosite.

Rhodochrosite with Fluorite on Quartz, Photo by Jeff Scovil, From the collection of: Rice Museum of Rocks and Minerals

Rhodochrosite Stalactite Slice, From the collection of: Rice Museum of Rocks and Minerals

Rhodochrosite with Tetrahedrite, Owned by Bruce Carter, Photo by Jeff Scovil, From the collection of: Rice Museum of Rocks and Minerals

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Rhodochrosite is a manganese carbonate ore mineral ranging in color from rosy pink to bright red.

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From China to South Africa to Argentina, rhodochrosite can be found all over the world. In the United States a famous locality is near Alma, Colorado. In fact, rhodochrosite is the state mineral! The Alma Rose hails from this locality.

Sweet Home Mine EntranceRice Museum of Rocks and Minerals

The Sweet Home Mine

Sweet Home is located near Alma, Colorado. Originally a silver mine, it was worked off and on from the 1870s through the 1960s but produced only modest amounts of ore. Early miners occasionally recovered small rhodochrosite crystals they traded for drinks at the bar in town.

Miner Pointing to Rainbow PocketRice Museum of Rocks and Minerals

Rainbow Pocket Discovery

On August 21, 1992, specimen hunters broke into a vug dubbed the Rainbow Pocket. This pocket changed the mine's fortunes forever: within an hour, owner and miner Bryan Lees reached in and pulled out an astonishing 15 cm rhombohedral crystal he later named the Alma King.

Rainbow Pocket Close-UpRice Museum of Rocks and Minerals

Hard Work and Stellar Rewards

Miners cleaned out the pocket over several weeks. It produced hundreds of specimens, including the Alma Rose.

Cutting off matrix rock, From the collection of: Rice Museum of Rocks and Minerals

trimming, From the collection of: Rice Museum of Rocks and Minerals

repairing, From the collection of: Rice Museum of Rocks and Minerals

and cleaning the Alma Rose Rhodochrosite, From the collection of: Rice Museum of Rocks and Minerals

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Due to the geology of the area and rhodochrosite's fragile nature, before the Alma Rose could be sold, it first was cleaned, repaired, and the matrix rock removed.

Denver Gem and Mineral Show MemorabiliaRice Museum of Rocks and Minerals

The sale

The sale of the specimens saved the mine financially and inaugurated a decade of discovery at the Sweet Home. Richard and Helen bought more than one rhodochrosite specimen that day, but it was the Alma Rose that won their hearts and never left their collection!

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