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
SourcingOct 02, 2026
De Beers, National Geographic Society Renew Okavango Eternal Partnership The partnership, a pledge to protect Africa’s Okavango River Basin, has been extended for an additional five years.
MajorsOct 02, 2026
Pandora Opens New $150M Manufacturing Facility in VietnamThe new facility, its first outside of Thailand, will boost its manufacturing capacity by 50 percent.
TrendsOct 02, 2026
Hearts On Fire Celebrates 30th Anniversary With Heart PendantThe special-edition “Dream” pendant, our Piece of the Week, was created to mark Hearts On Fire’s 30-year milestone with 30 diamonds.
Brought to you by
Meet Gemology’s Next Generation Microscope: GIA® Gemolite® NXT Professional EditionExperience gemstones with greater precision and comfort than ever before.
CrimeOct 01, 2026
Police Looking for 4 Suspects in $600K Smash-and-Grab RobberyDubai Jewelers in Springfield, Virginia, was once again the target of an armed robbery.
Weekly QuizOct 01, 2026
This Week’s QuizTest your jewelry news knowledge by answering these questions.
SurveysOct 01, 2026
Rolex Ranks Among Most Recommended Brands in US, Survey Says YouGov’s 2026 U.S. Most Recommended Brands report’s out, and a fast-fashion giant is sitting at No. 1 while Rolex is just shy of the top 5.
SourcingOct 01, 2026
Columbia Gem House Opens ‘Cutting Toward Change’ FundraiserProceeds from its jewelry raffle will benefit an organization working in India to combat silicosis, a lung disease affecting stone cutters.
Brought to you by
Your Piece Could Be the One Editors Talk AboutSubmit your pieces for a chance to win in this year's competition.
TrendsOct 01, 2026
Carolina Hurricanes’ Championship Ring Reveals Hidden Hockey Puck PendantThe rings, crafted by Jason of Beverly Hills, celebrate the hockey team’s Stanley Cup win with design elements that honor its traditions.
TrendsOct 01, 2026
Amanda’s Style File: October’s Color Range This roundup of birthstone jewelry for October features vibrant tourmalines and opals with personality.
SourcingSep 30, 2026
Botswana’s President, De Beers CEO Say Diamond Demand Is RecoveringPresident Duma Boko spoke at back-to-back events in the city last week, touting Botswana’s stability and the diamond “bounceback.”
CollectionsSep 30, 2026
Oscar Heyman’s Holiday Book Is ‘A Living Archive’ The catalog showcases 112 new, one-of-a-kind pieces amid highlights from the jeweler’s historic archive.
SourcingSep 30, 2026
Gemfields Posts $98.5M Loss, Writes Down Value of Ruby MineIts Montepuez Ruby Mining operation in Mozambique, which is not yielding enough high-quality rubies, has taken a $125 million hit.
SurveysSep 30, 2026
Consumer Confidence Falls to 12-Year Low in SeptemberThose surveyed were worried about the present and the future, with write-in responses mentioning high oil and gas prices.
Events & AwardsSep 30, 2026
Jewelers of America, JA New York to Host Networking EventThe event will take place on the evening of Oct. 26 in New York City.
IndependentsSep 29, 2026
Christy Bromberg, Longtime Gift Buyer for Underwood Jewelers, Dies at 68She is remembered for her joie de vivre, upbeat personality, genuine interest in other people, and love of the Alabama Crimson Tide.
AuctionsSep 29, 2026
Dionne Warwick’s Jewelry Goes Up for AuctionOnline bidding is open now for Julien’s sale of items owned by the “Walk On By” singer, whose final album comes out this fall.
Events & AwardsSep 29, 2026
Matt Stuller to Receive 2027 Gem Award for Lifetime AchievementThe founder and executive chairman of Stuller Inc. is being honored for his impact on the jewelry industry at the 25th annual Gem Awards.
ColumnistsSep 29, 2026
Your Holiday Marketing Has a Bridal Blind SpotDecember is the most popular month to propose, and jewelers need to keep that in mind when planning their holiday marketing.
AuctionsSep 29, 2026
If You Love Cats, This Jewelry Auction Is for YouCat ladies of the jewelry world, unite. Sandy Lerner’s collection of cat jewelry and other objects is going up for auction Wednesday.
CollectionsSep 28, 2026
De Beers London Drops Water-Inspired High Jewelry Collection“Vibrations” features several firsts for De Beers’ high jewelry, including the use of chalcedony and diamonds sourced from artisanal miners.
CollectionsSep 28, 2026
Jessica McCormack Turns to Classic Motif for New CollectionThe “Bows” collection features three interpretations of the bow motif designed with Georgian and Victorian influences.
Events & AwardsSep 28, 2026
Guy Borenstein, Troy Underwood Among the Professionals Honored at AGS Conclave 2026The American Gem Society recognized industry members, one Guild, and a law enforcement official for their contributions to jewelry.
FinancialsSep 28, 2026
Instappraise, Jewelers Mutual Look to Simplify Jewelry InsuranceThrough a new system integration, customers can now receive instant personal jewelry insurance quotes at the time of appraisal.
WatchesSep 25, 2026
Smaller Rolex Watches Showing Strength on Secondary Market, Data ShowsFive of the 10 fastest-appreciating Rolex models on Bob’s Watches were Datejust 31 or Lady Datejust watches.
MajorsSep 25, 2026
Sherwood Family Buys Back Daniel’s Jewelers from Private EquityThe Sherwood family and AJS Creations CEO Tejas Shah purchased the jewelry chain back from Palladium Equity Partners.
Lab-GrownSep 25, 2026
Brilliant Earth Collabs with Elizabeth Taylor Estate on Jewelry Collection“The Elizabeth Taylor Collection” uses lab-grown diamonds and gemstones in contemporary designs inspired by the icon.
