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.
EditorsSep 15, 2020
5 Things to Know About … Red Beryl
EditorsMar 16, 2020
5 Things to Know About … ForditeMore on Editors
The Latest
Supplier BulletinNov 21, 2024
Tasha R Releases 2025 Labbelle Lab Diamond Jewelry CatalogSponsored by Tasha R
AuctionsNov 21, 2024
Gold Watch Gifted to Titanic Rescue Ship Captain Sells for $2MThree Titanic survivors presented him with the personalized Tiffany & Co. timepiece about a year after the tragedy.
MajorsNov 21, 2024
Harris Jewelry Ordered to Reopen Claims Portal for Refund RequestsA federal court found that the jewelry store chain violated terms of the settlement reached after it was accused of defrauding customers.
Brought to you by
Navigating Cybersecurity: Essential Guidance for JewelersFrom protecting customer data to safeguarding inventory records, it's crucial to learn how to tackle cybersecurity challenges.
CollectionsNov 21, 2024
Channel Elphaba in Muse’s ‘Have a Heart x Cynthia Erivo’ CollectionCynthia Erivo chose Dreams of Hope, an organization dedicated to empowering LGBTQA+ youth, as the charity for this year’s collection.
Weekly QuizNov 21, 2024
This Week’s QuizTest your jewelry news knowledge by answering these questions.
MajorsNov 21, 2024
Rocksbox Opens Pop-Up Store in San FranciscoThe new space was designed to evoke a warm, inviting vibe.
IndependentsNov 21, 2024
Mary Moses Kinney Is Now Part of The Edge’s Team Kinney, who spent nearly 30 years at IJO, has been hired to head Abbott Jewelry Systems’ new virtual marketplace.
Brought to you by
Enhance Your Expertise with IGI’s In-Person Courses in NYCThis fall, sharpen your skills in jewelry grading, quality control and diamond assessment.
CrimeNov 20, 2024
Sotheby’s to Pay $6.25M Settlement to NY State for Alleged Tax FraudThe auction house was accused of helping clients avoid paying taxes on millions of dollars’ worth of art purchased from 2010 to 2020.
Events & AwardsNov 20, 2024
Kering Debuts New Jewelry Award With Sustainability FocusThe four finalists will present their pieces at the 2025 JCK Las Vegas show.
CollectionsNov 20, 2024
Pamela Love Channels Surrealist Artists in New CollectionThe “Camera Oscura” collection showcases earring designs celebrating female Surrealist artists Claude Cahun and Leonor Fini.
Policies & IssuesNov 20, 2024
Columbia Gem House Raises $10K for Reforestation EffortsThe money will fund the planting of 10,000 trees in critical areas across Oregon, Arizona, Montana, and other regions.
Events & AwardsNov 20, 2024
The Jewelry Symposium Opens Registration, Scholarship ApplicationsThe event centered on advancing jewelry manufacturing technology will return to Detroit in May 2025.
CrimeNov 19, 2024
Woman Killed in Armed Robbery of Sacramento Jewelry StoreLocal reports identified the woman as the wife of the jewelry store owner.
AuctionsNov 19, 2024
‘A Tsar’s Treasure’ Fetches $2.9M at Sotheby’s Jewelry SaleA collection of pieces owned by Ferdinand I, the first king of modern Bulgaria, and his family, blew away estimates in Geneva last week.
MajorsNov 19, 2024
Trove Opens First US Flagship in NYCThe Australian jewelry box brand’s new West Village store will showcase new jewelers each month through its Designer in Residence program.
CollectionsNov 19, 2024
Snoop Dogg’s New Jewelry Collection Is All About Love“Lovechild” was created in partnership with Carolyn Rafaelian’s Metal Alchemist brand.
Policies & IssuesNov 18, 2024
Reciprocity Jewels Returns to NYC Jewelry WeekThe group will host several curated events and an exhibition of designer jewelry made with Peruvian gold traceable to the miners’ names.
CollectionsNov 18, 2024
Dolly Parton Shines in Collaboration with Kendra ScottThe collection honors the 50th anniversary of Dolly Parton’s “Love is Like a Butterfly” song, which shares a birth year with Kendra Scott.
Events & AwardsNov 18, 2024
IGI Jewelry Design Competition ReturnsThis year’s theme asks designers to take inspiration from classic fairy tales.
CollectionsNov 15, 2024
Marie Lichtenberg Battles Counterfeits with New ‘Raiz’in Scapular’ DesignsThe latest “Raiz’in” drop showcases a newly designed “Scapular” necklace and donates a portion of the proceeds to Make-A-Wish France.
WatchesNov 15, 2024
Piece of the Week: Citizen’s Commemorative Pocket WatchNo. 1 out of 100, the timepiece was created to mark Citizen’s 100th anniversary and will be auctioned off at Sotheby’s next month.
Recorded WebinarsNov 15, 2024
Watch: 10 Tips to Keep Your Jewelry Store Secure On the latest episode of “My Next Question,” two experts share best practices for store security during the holidays and year-round.
AuctionsNov 14, 2024
18th-Century Diamond Necklace Sells for Nearly $5M Sotheby’s sold the necklace, which potentially has ties to Marie-Antoinette, for $4.8 million to a woman bidding via phone.
MajorsNov 14, 2024
Saks Fifth Avenue Cancels Holiday Light DisplayInstead of its usual elaborate display, the store will illuminate its façade and frame the windows to highlight its flagship’s architecture.
WatchesNov 14, 2024
Grand Seiko Partners With Ben Bridge on First Hawaii Store The new Grand Seiko boutique is located in Honolulu’s Waikiki neighborhood.
SourcingNov 13, 2024
Gem Legacy Adventures Announces 2025 Trip Eleven spots are available for travelers to visit Northern Tanzania and Southern Kenya from July 25 to Aug. 4.
