SourcingMay 09, 2022
First Diamonds from Sierra Leone’s Tongo Mine Coming to MarketSourcingMay 17, 2022
A New Source in Tanzania Is Producing Cobalt-Blue Spinel
The stones come from a deposit close to Mahenge and have been on the market for several months.
Examples of the cobalt-blue spinel from Tanzania (Image courtesy of Mahenge Gems)
New York—Tanzania’s Mahenge region is known in the gem world for its beautiful red and pink spinel, but the area has begun producing another color recently—cobalt blue.
The newly discovered deposit is about 12.5 miles southeast of Mahenge.
The spinel started appearing on the market late last year, according to wholesaler Mahenge Gems, which was established in early 2020 and has direct access to miners in the area.
The material began arriving in the Mahenge Gems office around late October/early November, Director Wez Barber said.
At the beginning, they thought it was standard blue spinel because of the large size of the crystals.
The leading source of cobalt-blue spinel is Vietnam’s Luc Yen District, known for its vibrant blue material, though those stones tend to be small.
This Tanzanian material, Barber said, is the “best of both worlds”—good quality, clean, saturated stones that are more than 1.5 carats in size, including some as big as 40 carats.
The colors so far have ranged from a denim blue to a vibrant electric blue, Barber noted.
“We bought as much of it as we could lay our hands on, and still are, because it was such nice material,” he said.
The company sent stones to a few different labs to have it confirmed as cobalt-blue spinel.
Related stories will be right here …
The newly discovered deposit is about 12.5 miles southeast of Mahenge.
The spinel started appearing on the market late last year, according to wholesaler Mahenge Gems, which was established in early 2020 and has direct access to miners in the area.
The material began arriving in the Mahenge Gems office around late October/early November, Director Wez Barber said.
At the beginning, they thought it was standard blue spinel because of the large size of the crystals.
The leading source of cobalt-blue spinel is Vietnam’s Luc Yen District, known for its vibrant blue material, though those stones tend to be small.
This Tanzanian material, Barber said, is the “best of both worlds”—good quality, clean, saturated stones that are more than 1.5 carats in size, including some as big as 40 carats.
The colors so far have ranged from a denim blue to a vibrant electric blue, Barber noted.
“We bought as much of it as we could lay our hands on, and still are, because it was such nice material,” he said.
The company sent stones to a few different labs to have it confirmed as cobalt-blue spinel.
Swiss gem lab SSEF analyzed a selection of the material, confirming cobalt as the main coloring element, in combination with iron.
This makes the Mahenge material similar to cobalt spinel from sources in Sri Lanka, Pakistan, and Vietnam, the lab said.
The Tanzanian material contains characteristic inclusions, SSEF noted, like oriented geometric lamellae with interference colors together with lines of fine particles. It said similar inclusions have been found in red spinel from Morogoro in eastern Tanzania.
Through Raman spectroscopy, SSEF also found colorless apatite and clusters of small zircon inclusions.
Because the deposit was discovered fairly recently, it remains to be seen how much material it will produce.
Barber said that in the past six weeks to two months, very little material has been coming through their office, but he also noted there had been little mining activity due to the rainy season and Ramadan.
With Ramadan ending in early May and the rainy season coming to a close, they should soon be able to ascertain how much more material the deposit might produce.
Those interested in the cobalt-blue spinel can contact Mahenge Gems via its website or follow the company on Instagram.
Mahenge Gems will also have the Tanzanian cobalt-blue spinel on display during the upcoming Las Vegas Market Week. Visit them in the Gems pavilion at JCK Las Vegas at Booth 33105.
More on Sourcing
The Latest
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.
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.
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.
Weekly QuizNov 14, 2024
This Week’s QuizTest your jewelry news knowledge by answering these questions.
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.
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.
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.
EditorsNov 18, 2024
Q&A: Helzberg CEO Brad Hampton on the Jeweler’s RebrandHampton discussed how Helzberg is improving the customer experience and why it was inspired by the company formerly known as Dunkin’ Donuts.
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.
EditorsNov 15, 2024
Why Fine Jewelry Belongs at New York Comic ConSenior Editor Lenore Fedow makes the case for why more jewelers should be appealing to nerds at the annual event.
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.
AuctionsNov 13, 2024
Aga Khan Emerald Sells for $8.8M, Sets RecordThe emerald brooch-turned-pendant returned to auction after 55 years, setting a world record for most expensive emerald sold at auction.
AuctionsNov 13, 2024
‘Exceptional’ Burmese Ruby Ring Tops $5M at Auction Phillips also sold a 1.21-carat fancy red diamond dubbed the “Red Miracle” for more than $1 million at its jewelry auction in Geneva.
MajorsNov 13, 2024
Ariana Grande, Anya Taylor-Joy Star in Holiday Jewelry CampaignsFrom Swarovski to Tiffany & Co., jewelry retailers are enlisting celebrities to highlight their holiday offerings.
MajorsNov 13, 2024
Royal Chain’s New Catalog Is Out NowThe 2024-2025 book introduces hundreds of new designs.
FinancialsNov 12, 2024
Cartier, Van Cleef & Arpels Continue to Shine for Richemont Richemont’s jewelry sales ticked up 2 percent in the first half of the year, while watch sales plummeted 17 percent.
