GradingJul 30, 2024
Gübelin Academy Bringing Colored Gemstone Course to NYCGradingAug 13, 2024
Star-Shaped Inclusions Spotted in Diamonds
GIA recently examined two asteriated diamonds, weighing about 8 carats each, that it said were notable for their large size and preserved natural forms.
The asteriated diamonds displayed light brown cloud inclusions shaped like stars.
Carlsbad, Calif.—Two natural diamonds with star-shaped inclusions were recently submitted to the Gemological Institute of America’s Carlsbad laboratory for examination.
The asteriated or “star” diamonds, weighing 8.14 carats and 8.57 carats, appeared in the lab’s summer 2024 edition of “Gems & Gemology.”
The stones displayed light brown cloud inclusions, which come from high concentrations of hydrogen and nickel during their growth period, said GIA, and may also contain graphite.
GIA said asteriated diamonds are occasionally submitted to the lab, but these two stones are notable for their large size and preserved natural forms.
The 8.14-carat diamond was resorbed—partially dissolved by natural fluid or magma, causing it to take on a rounded shape—and maintained most of its rough form on one side.
The stone was sliced to show the underlying inclusion pattern on the other side.
The preserved rough surfaces also displayed brown radiation stains, which are an indication that it had natural alpha irradiation followed by annealing in the earth.
The 8.57-carat diamond was polished with bruted edges.
Related stories will be right here …
The asteriated or “star” diamonds, weighing 8.14 carats and 8.57 carats, appeared in the lab’s summer 2024 edition of “Gems & Gemology.”
The stones displayed light brown cloud inclusions, which come from high concentrations of hydrogen and nickel during their growth period, said GIA, and may also contain graphite.
GIA said asteriated diamonds are occasionally submitted to the lab, but these two stones are notable for their large size and preserved natural forms.
The 8.14-carat diamond was resorbed—partially dissolved by natural fluid or magma, causing it to take on a rounded shape—and maintained most of its rough form on one side.
The stone was sliced to show the underlying inclusion pattern on the other side.
The preserved rough surfaces also displayed brown radiation stains, which are an indication that it had natural alpha irradiation followed by annealing in the earth.
The 8.57-carat diamond was polished with bruted edges.
Both diamonds’ clouds fluoresced green when subjected to long-wave UV, which GIA said is consistent with previously studied asteriated diamonds.
Also, both stones showed high concentrations of hydrogen, which the lab detected using bulk Fourier-transform infrared spectroscopy.
Using photoluminescence mapping for the 8.14-carat stone, the lab saw that several nickel-related defects were detected inside the cloud inclusion sector but not outside of it.
GIA also analyzed the diamonds using X-ray computed microtomography, which allowed the asteriated growth sectors to be viewed in 3-D reconstructions.
It found the asteriated regions more strongly absorb X-rays than the rest of the diamond.
This indicates, the lab said, the combined signal from the diamond and inclusions likely had a higher atomic number.
Editors' Picks
Sponsored by
More on Grading
The Latest
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.
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
Meet Gemology’s Next Generation Microscope: GIA® Gemolite® NXT Professional EditionExperience gemstones with greater precision and comfort than ever before.
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.
Weekly QuizOct 01, 2026
This Week’s QuizTest your jewelry news knowledge by answering these questions.
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.”
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.
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.
TrendsSep 25, 2026
A Peek at Taylor Swift’s Game-Day DiamondsThe artist wore Dana Rebecca Designs’ marquise diamond-set gold hoops at the Chiefs game last Sunday. Now they’re our Piece of the Week.
CrimeSep 24, 2026
From Conclave: Security Measures Jewelers Should Be TakingJSA and Jewelers Mutual shared advice on spotting suspicious behavior, combatting cell phone jammers, and staying safe at home.
