AuctionsFeb 03, 2021
Buyers Went Crazy for Hester Diamond’s Mineral CollectionEditorsMar 25, 2021
5 Things to Know About … Rhodochrosite
Learn about one relatively new project bringing more material from a storied site.
A rhodochrosite mineral specimen from the Zacks pocket at the Detroit City Portal in Colorado (Photo courtesy of Collector’s Edge Minerals Inc.)
I am a gemstone lover, no question. But over the past few years, I’ve also really come to appreciate a good mineral specimen.
There’s something about specimens that crystallize in perfect cubic shapes that is so alluring, especially when they’re in matrix. This is probably where my interest in rhodochrosite grew from.
In its purest (and best, in my opinion) form, the manganese carbonate is a vibrant red color, and the fine mineral specimens are stunning.
The rhodochrosite market has plenty of interest for faceted or polished goods and mineral specimens, though both are rare. With some new activity in the space, this interest is likely to continue.
Here are five things you should know about the mineral.
1. Its looks can take a few different forms.
Rhodochrosite gets its color from manganese, but because the mineral has a variable chemical composition, the manganese can be replaced in small amounts by iron, magnesium and/or calcium.
These substitutions alter the specific gravity, hardness, and color of the mineral.
In fact, its color can range from light pink to bright red, and can even become grayish, yellowish, or brownish as the chemical composition varies.
Additionally, the environment during rhodochrosite’s formation can have a major effect on the way it looks.
There’s something about specimens that crystallize in perfect cubic shapes that is so alluring, especially when they’re in matrix. This is probably where my interest in rhodochrosite grew from.
In its purest (and best, in my opinion) form, the manganese carbonate is a vibrant red color, and the fine mineral specimens are stunning.
The rhodochrosite market has plenty of interest for faceted or polished goods and mineral specimens, though both are rare. With some new activity in the space, this interest is likely to continue.
Here are five things you should know about the mineral.
1. Its looks can take a few different forms.
Rhodochrosite gets its color from manganese, but because the mineral has a variable chemical composition, the manganese can be replaced in small amounts by iron, magnesium and/or calcium.
These substitutions alter the specific gravity, hardness, and color of the mineral.
In fact, its color can range from light pink to bright red, and can even become grayish, yellowish, or brownish as the chemical composition varies.
Additionally, the environment during rhodochrosite’s formation can have a major effect on the way it looks.
A selection of faceted rhodochrosite gemstones from the Detroit City Portal in Colorado (Photo courtesy of Iteco Inc.)
A large rhodochrosite crystal (Photo courtesy of Collector’s Edge Minerals Inc.)
Rough rhodochrosite for faceting (Photo courtesy of Collector’s Edge Minerals Inc.)
When it forms along mineral veins in pockets, rhodochrosite crystals can take shape.
It can also form as stalactites when water drips from manganese-rich rocks, creating banded material; that is often cut as slabs or used for ornamental objects, cabochons, beads, and more.
2. It’s found at a handful of sources, but supply of fine goods is low.
The list of sources for rhodochrosite doesn’t seem insignificant when you line them up, especially when compared to some other gemstones.
But the reality is that, like most colored gems, supply is limited.
“Rhodochrosite was the first stone in my cutting career where I realized you should buy things when they’re available and not when you need them. Because when you need them, they won’t be available,” gemstone cutter and wholesaler John Bradshaw said in a recent interview.
Rhodochrosite used for lapidary and mineral specimens has been found in Argentina, South Africa, Peru, Montana, Russia, China, Gabon, Mexico, and Japan, among others, according to several gemological and geological sources.
Argentina is a large source of the banded material, where stalagmites form in long-abandoned Incan silver mines, the International Gem Society said. (The mineral is often associated with silver deposits.)
The material from South Africa, meanwhile, is known for being rich in color but more of a darker hue, which some call blood red.
That material is “probably the oldest and most well-known … or was the most well-known,” Bradshaw said, noting there is virtually no production anymore; he sources South African rhodochrosite from old inventories.
In the United States, sources have been found in Montana and Colorado, the latter of which is known for the red material that comes from the Sweet Home Mine on Mount Bross.
Sweet Home started as a silver mine in the 1870s, at which time the rhodochrosite was just seen as waste rock, according to Steve Behling, the sales manager at Collector’s Edge Minerals.
The mine wasn’t very productive, failing to make a profit for the first few decades, according to the Gemmological Association of Great Britain, and also faced an onslaught of competition in the late 1800s as more and more mines opened.
Soon enough, though, those red crystals were recognized for their worth and started gaining value, becoming the mine’s sole focus.
Sweet Home produces some of the finest rhodochrosite in the world—vibrant, cherry red crystals—and helped it gain its status as the Colorado state mineral in 2002.
The mine has also been known to turn out some large pieces.
In 1992, it produced its largest yet, the Alma King—a rhodochrosite crystal measuring 14.25 centimeters on one side sitting on a quartz matrix more than 2 feet long, according to GIA’s Gems & Gemology.
The Alma King is currently in the collection of the Denver Museum of Natural History.
Modern production at the site has been handled by Bryan Lees and his two companies: Colorado Calumet Co. does the mining and Collector’s Edge Minerals markets and sells the mineral specimens. (The facetable rough is sent to Ohio-based Iteco Inc. for cutting.)
Active mining ceased at Sweet Home in 2004, but there’s been some activity nearby that should excite rhodochrosite lovers.
3. There’s new production at a storied source.
Lees initially leased the Sweet Home Mine but bought it outright in 1991. He operated the mine for more than a decade, pulling out collectable crystal specimens and facetable rough material.
In 2004, realizing they had reached the end of mining at that level of Mount Bross, Lees and his companies ceased operations at Sweet Home.
Between 1991-2004, Colorado Calumet/Collector’s Edge pulled out about $100 million dollars’ worth of mineral specimens in current dollar value, sales manager Behling said.
But Lees always wanted to go back, he added, knowing there were more red stones to be found in the mountain. So, he studied its geology and in 2016 received government approval to start mining again.
The new project is 200 feet above where they had been mining prior. Their first task was to drill and blast a 400-foot tunnel into the side of the mountain to get to the mineralized veins.
Sweet Home started as a silver mine in the 1870s, at which time the rhodochrosite was just seen as waste rock, according to Steve Behling, the sales manager at Collector’s Edge Minerals.
The mine wasn’t very productive, failing to make a profit for the first few decades, according to the Gemmological Association of Great Britain, and also faced an onslaught of competition in the late 1800s as more and more mines opened.
Soon enough, though, those red crystals were recognized for their worth and started gaining value, becoming the mine’s sole focus.
Sweet Home produces some of the finest rhodochrosite in the world—vibrant, cherry red crystals—and helped it gain its status as the Colorado state mineral in 2002.
The mine has also been known to turn out some large pieces.
In 1992, it produced its largest yet, the Alma King—a rhodochrosite crystal measuring 14.25 centimeters on one side sitting on a quartz matrix more than 2 feet long, according to GIA’s Gems & Gemology.
The Alma King is currently in the collection of the Denver Museum of Natural History.
Modern production at the site has been handled by Bryan Lees and his two companies: Colorado Calumet Co. does the mining and Collector’s Edge Minerals markets and sells the mineral specimens. (The facetable rough is sent to Ohio-based Iteco Inc. for cutting.)
Active mining ceased at Sweet Home in 2004, but there’s been some activity nearby that should excite rhodochrosite lovers.
3. There’s new production at a storied source.
Lees initially leased the Sweet Home Mine but bought it outright in 1991. He operated the mine for more than a decade, pulling out collectable crystal specimens and facetable rough material.
In 2004, realizing they had reached the end of mining at that level of Mount Bross, Lees and his companies ceased operations at Sweet Home.
Between 1991-2004, Colorado Calumet/Collector’s Edge pulled out about $100 million dollars’ worth of mineral specimens in current dollar value, sales manager Behling said.
But Lees always wanted to go back, he added, knowing there were more red stones to be found in the mountain. So, he studied its geology and in 2016 received government approval to start mining again.
The new project is 200 feet above where they had been mining prior. Their first task was to drill and blast a 400-foot tunnel into the side of the mountain to get to the mineralized veins.
This image shows where the new Detroit City Portal is compared with the original Sweet Home Mine site. (Photo courtesy of Collector’s Edge Minerals Inc.)
Mining activity at the Detroit City Portal (Photo courtesy of Collector’s Edge Minerals Inc.)
They started to find pockets in late 2018, Behling said, and mineral specimens started hitting the market that year.
Facetable rough took longer to find, and cut stones from the new project just started coming out last summer, Iteco’s Paul Cory confirmed.
The two working areas are not connected underground—just located on the same mining site—so they gave the new one a different name but retained Sweet Home for marketing reasons; it’s been dubbed the Detroit City Portal at the Sweet Home Mine.
So far, production hasn’t quite been at the level of Sweet Home, Behling said, but noted it can be scattershot anyway.
“I can tell you for a fact that even in the original mine, it sometimes would be six months to a year in between major pockets. You’d move a lot of rock and once in a while, nature would give you a gift where you had this beautiful pocket of crystals. It’s a very feast-or-famine kind of mining.”
When speaking to facetable material from Detroit City, Cory said Sweet Home produced more rough per season than the new working area.
Part of that does have to do with the mining company’s increased ability to get crystals out undamaged, meaning they will be kept as mineral specimens rather than being cut.
But he put it this way: “To give you a scale of the supply, probably all of [National Jeweler’s] readers could carry the entire gem rough supply in a single box from the vault to their car parked nearby.”
4. Rhodochrosite mineral specimens can go for much more than faceted material.
Mineral collectors love when the specimens feature a crystal in matrix, rather than isolated or broken fragments, Behling said.
These kinds of pieces are rare, and when they do find them, collectors gobble them up.
Some of the specimens from Sweet Home sold for $500 or $1,000 per piece, Behling said. But it’s also not unusual, he added, for Collector’s Edge to sell individual pieces for six figures.
“You may have a 3-inch-by-3-inch piece of matrix with several crystals on it, and it’ll be $100,000 or it’ll be $150,000.”
5. But faceted material is still highly coveted.
Sources also rarely turn out transparent material that can be faceted, and these pieces, too, are in high demand from buyers.
Gemstone cutter and wholesaler Bradshaw said when he recently held a virtual Tucson event, he sold out of several stones, and rhodochrosite was one of them.
Iteco’s Cory said, “The demand far exceeds the supply, and the market grows every year. The demand is worldwide, focused primarily on Japan, India, and the U.S. market. As more people become aware of the beauty of faceted rhodochrosite, the market becomes even larger.”
But rhodochrosite is not only low in supply; it also contains a few gemological characteristics that present a challenge for faceting.
First, it has perfect cleavage in three directions, so cutters must make sure they don’t put a large facet parallel to a cleavage plane, Cory said, which makes it more difficult to polish.
It also has a hardness of only 3.5-4 on the Mohs scale, so the stone is best set in earrings or necklaces, pieces that tends to take less abuse than rings or bracelets.
“You may have a 3-inch-by-3-inch piece of matrix with several crystals on it, and it’ll be $100,000 or it’ll be $150,000.”
5. But faceted material is still highly coveted.
Sources also rarely turn out transparent material that can be faceted, and these pieces, too, are in high demand from buyers.
Gemstone cutter and wholesaler Bradshaw said when he recently held a virtual Tucson event, he sold out of several stones, and rhodochrosite was one of them.
Iteco’s Cory said, “The demand far exceeds the supply, and the market grows every year. The demand is worldwide, focused primarily on Japan, India, and the U.S. market. As more people become aware of the beauty of faceted rhodochrosite, the market becomes even larger.”
But rhodochrosite is not only low in supply; it also contains a few gemological characteristics that present a challenge for faceting.
First, it has perfect cleavage in three directions, so cutters must make sure they don’t put a large facet parallel to a cleavage plane, Cory said, which makes it more difficult to polish.
It also has a hardness of only 3.5-4 on the Mohs scale, so the stone is best set in earrings or necklaces, pieces that tends to take less abuse than rings or bracelets.
Additionally, rhodochrosite is strongly doubly refractive—light enters it and splits into two—so cutters must orient the rough to avoid making a stone look “sleepy” if pavilion facets appear doubled, Cory said.
Even with this extra care required, cutters definitely will roll the dice on rhodochrosite when given the chance.
“In previous years, I would never consider cutting melee rhodochrosite, but I do now,” Bradshaw said. “Because it sells.”
Cory said stones bigger than 3 carats have about doubled in price over the last five years, while those weighing more than 10 carats have risen even more, perhaps triple from when the original Sweet Home Mine project closed in 2004.
Even with this extra care required, cutters definitely will roll the dice on rhodochrosite when given the chance.
“In previous years, I would never consider cutting melee rhodochrosite, but I do now,” Bradshaw said. “Because it sells.”
Cory said stones bigger than 3 carats have about doubled in price over the last five years, while those weighing more than 10 carats have risen even more, perhaps triple from when the original Sweet Home Mine project closed in 2004.
Editors' Picks
Sponsored by
EditorsSep 15, 2020
5 Things to Know About … Red Beryl
EditorsMar 16, 2020
5 Things to Know About … ForditeMore on Editors
The Latest
AuctionsJun 18, 2026
Paraíba Tourmalines Sell for $3.4M at Sotheby'sThe recent high jewelry auction, which also featured the sale of a 10-carat blue diamond, was “a celebration of color.”
CollectionsJun 18, 2026
Michelle Obama Wears Almasika Earrings Symbolizing Feminine PowerShe wore the “Le Cauri Endiamanté” earrings, our Piece of the Week, in the Obamas’ first dual portrait for the Obama Presidential Center.
PodcastsJun 17, 2026
Episode 6: Las Vegas 2026-Trends, Traffic, Broken BathroomsCouture’s Michelle Orman joins Amanda Gizzi and Michelle Graff for this special post-Market Week episode of My Next Question.
Brought to you by
Wedding Band Trends 2026: Personalization Takes Center StageColored gemstones, artisan finishes, mixed metals, and meaningful details are shaping demand in bridal jewelry.
GradingJun 17, 2026
SSEF Issues Warning on Refilled EmeraldsThe lab is seeing emeralds with filler added post-testing enter the market, accompanied by reports that indicate little to no treatment.
Weekly QuizJun 17, 2026
This Week’s QuizTest your jewelry news knowledge by answering these questions.
WatchesJun 17, 2026
Patek Philippe’s ‘Visionary’ Leader Philippe Stern Dies at 88 The third generation of the Stern family to head Patek Philippe, he navigated the “quartz crisis” and preserved the brand’s independence.
MajorsJun 17, 2026
James Avery to Revamp In-Store Retail ExperienceThe Texas-based jeweler is gradually rolling out a new experience-forward layout in its stores.
Brought to you by
Building the Future of Jewelry Retail: DCA Expands Education, Leadership Development, and Workforce SolutionsDCA is preparing the next generation of professionals by supporting workforce development, leadership growth, and career advancement.
MajorsJun 17, 2026
Seahawks’ Super Bowl Ring Blends Meaningful Design, Technical CraftsmanshipThe Super Bowl LX champions were honored with diamond and blue sapphire rings by Jason of Beverly Hills.
Policies & IssuesJun 17, 2026
Community for Ethical Jewelry Names New Executive DirectorMarianna Smirnova previously spent a decade working with the Responsible Minerals Initiative, in addition to other relevant roles.
MajorsJun 16, 2026
5 Things to Know About the 2026 NBA Championship TrophyThe New York Knicks took home the Larry O'Brien Trophy crafted by Tiffany & Co.
TrendsJun 16, 2026
Post-Vegas Jewelry Trend Report: Big Beads, Western Flair, White MetalsAssociate Editor Natalie Francisco lists the trends she spotted during Jewelry Market Week that will dominate the second half of 2026.
SourcingJun 16, 2026
GemGuide Updates Ruby PricesIts app now reflects increased prices for Mozambique ruby, as well as changes to its Burma ruby charts.
MajorsJun 16, 2026
Sasha Primak Hires New Design DirectorThe manufacturer has tapped Alicia Arnold, the former director of custom design at Tiny Jewel Box.
IndependentsJun 15, 2026
DeBoulle Diamond & Jewelry to Renovate Dallas FlagshipThe revamped, elevated space will feature a two-story Patek Philippe atelier and a rooftop patio for parties.
WatchesJun 15, 2026
G-Shock, Coca-Cola Partner on Bottle-Inspired WatchThe special-edition piece marks the 140th anniversary of the iconic beverage brand.
TrendsJun 15, 2026
Amanda’s Style File: Tiny Charms Are TrendingHere are 13 small charms to inspire your layered looks this summer.
AuctionsJun 12, 2026
16th-Century ‘Hogback’ Diamond Ring Going Up for Auction in LondonFound by a metal detectorist, the ring likely belonged to a wealthy, possibly royal, owner, said Noonans.
CollectionsJun 12, 2026
Chouette Designs To Launch Collection Celebrating All Types of LoveOur Pride Month Piece of the Week, the “Margaux” ring, is part of the wife-and-wife team’s new “Lovestoned” collection.
Events & AwardsJun 12, 2026
CBG Announces Plans for Phoenix ShowThe group has named the keynote speaker and announced a new pavilion for its next event, which is slated for September.
SourcingJun 11, 2026
Grandview Klein, London Jewelers Partner To Cut 63-Carat RoughThe big stone will be fashioned into a 20.26-carat diamond in celebration of the retailer’s 100th anniversary this year.
MajorsJun 11, 2026
Former Cartier Creative Director To Head Chanel’s Jewelry Creation StudioMarie-Laure Cérède will join Chanel as the new director of its jewelry creation studio, starting in October.
Lab-GrownJun 11, 2026
Smiling Rocks’ ‘Wish Jar’ Generates 100+ Wishes in Las Vegas At the JCK show, the lab-grown diamond brand teamed up with Jewelers for Children to support Make-A-Wish India.
SourcingJun 11, 2026
Signet Jewelers Exec Joins Diamonds Do Good BoardIlana McCabe is Signet’s vice president of public relations and brand communications.
AuctionsJun 10, 2026
31.62-Carat ‘Azure Blue’ Diamond Sells For $8M+ at Christie’sIt was a banner day for blue gemstones, with another blue diamond topping $8 million and a 41-carat sapphire going for $2.3 million.
MajorsJun 10, 2026
Saks Global Receives Bankruptcy Court Approval for ReorganizationThe approval means the retailer is on track to exit bankruptcy proceedings this summer.
CrimeJun 10, 2026
2 Suspects Arrested in Texas Jewelry Store RobberyThe men are believed to be part of the group of several masked suspects that robbed Marc Robinson Jewelers in April.
