Zabler Design Blog

In honor of April's official birthstone, we present the fascinating backstory of the historic and well-traveled "Blue Heart Diamond," a 30.62-carat stunner that Smithsonian benefactor Marjorie Merriweather Post described as "prettier than that other one" while escorting guests on a tour of the National Gem Gallery. The object of her snub was the "Hope Diamond."



The origin story of the Blue Heart Diamond can be traced back to October of 1909, when an exceptional 100.5-carat deep blue diamond was unearthed at De Beers' Premier Mine in South Africa. Two months later, the crystal was sold for £3,979 (equivalent of £600,000 or $775,000 today) to a French diamond cutter named Atanik Eknayan.

Eknayan faceted the gem into a 30.62-carat heart-shaped brilliant and sold it in 1910 to famed Fifth Avenue jeweler Pierre Cartier. Cartier placed the impressive stone as the center of a luxurious lily-of-the-valley corsage that included smaller pink and blue diamonds.

In 1911, the corsage caught the eye of the Argentinian heiress and philanthropist Maria Unzué de Alvear, who owned it for the next 25 years.

In 1936, at the age of 74, she presented the piece as a wedding gift to her niece, Angela Gonzales Alzaga. In his book, Unearthed, former Smithsonian National Gem Collection curator Dr. Jeffrey Post noted that the Blue Heart Diamond is sometimes referred to as the "Unzué Heart" due to its close ties to that family.

The Blue Heart Diamond was reset as a pendant after it was acquired by Van Cleef & Arpels in 1953. A member of the Unzué family told Post that the price exceeded that of a very fine house in Buenos Aires at the time.

That pendant, which featured the 30.62-carat Blue Heart Diamond dangling below a 2.05-carat pink diamond and 3.81-carat blue diamond, was sold in 1953 to Swiss industrialist Baron Hans Heinrich Thyssen-Bornemisza. The Baron gifted the pendant to fashion model Nina Sheila Dyer, who he would marry in 1954.

The marriage lasted only 10 months, but Dyer possessed the Blue Heart Diamond until she sold it to New York City luxury jeweler Harry Winston in 1959. Winston reset the stone into a ring and surrounded it with 25 round brilliant, colorless diamonds.

In 1964, Winston sold the ring to Marjorie Merriweather Post, the heiress to the Post cereal fortune and an avid collector of high-profile fine jewelry. As Jeffrey Post tells the story, only two months after the purchase, "Marjorie Merriweather Post arrived at the office of Smithsonian secretary Leonard Carmichael bearing gifts, her bag brimming with jewelry that she was gifting to the Smithsonian Institution."

One of those pieces was the Blue Heart Diamond. Interestingly, her donation included one stipulation: That she be able to borrow the jewelry at her discretion, which she did in 1964, 1968 and 1970.

Although the Blue Heart Diamond is only two-thirds the weight of the far more famous 45.52-carat Hope Diamond, jewelry aficionados generally agree that the Blue Heart Diamond displays a more lively blue color.

Ms. Post clearly agreed.

As Jeffrey Post explains, "Once, when walking through the museum's Gem Gallery, Ms. Post was overheard saying to her guests that 'my blue diamond is prettier than that other one.'"

Marjorie Merriweather Post's donation of the Blue Heart Diamond was one of many notable pieces gifted to the Smithsonian by the Post family. Others included the “Maximilian Emerald Ring,” “Napoleon Diamond Necklace,” “Marie-Louise Diadem” and the “Post Emerald Necklace.” Marjorie Merriweather Post passed away in 1973 at the age of 86.

Credit: Image by Chip Clark, courtesy of the Smithsonian.

"The Regent Kashmir" and "The Regal Ruby" are set to share the spotlight at Christie's Magnificent Jewels live auction in Hong Kong on May 27. Representing the pinnacle of beauty and quality, the 35.09-carat Kashmir sapphire and 13.22-carat Burmese ruby are true rarities.



Christie's classified The Regent Kashmir as a "once-in-a-generation masterpiece" and the most valuable piece of Kashmir sapphire jewelry offered at Christie’s globally in the past five years. Set in a ring, the sapphire is expected to fetch between $8.3 million and $12.2 million.



The Regal Ruby is poised to become the most valuable and largest Burmese ruby sold at Christie’s Hong Kong in a decade. Also set in a ring, the ruby carries a pre-sale estimate of $6.4 million to $10.2 million.

First discovered in the Zanskar mountain range of Kashmir, India, in 1881, sapphires from this region are famous for their intense "cornflower" or velvety blue hue and are considered the finest in the world.

Burmese rubies from the Mogok Valley in Myanmar (formerly Burma) are renowned for their richly saturated red color known as “pigeon’s blood." Top-quality unheated rubies exceeding 5 carats are remarkably rare.

Despite the eight-figure price estimates for the headliner gems, it's likely that the current sapphire and ruby record holders will retain their honors.

The most expensive ruby ever sold at auction was the "Estrela de Fura," a 55.22-carat gem, which fetched $34.8 million at Sotheby's in New York in June 2023. The record for the priciest sapphire to go under the hammer is held by the "Blue Belle of Asia," a 392.52-carat cushion-cut Ceylon sapphire, which earned $17.3 million at Christie's Geneva in November 2014.



Other highlights from Christie's Magnificent Jewels auction in Hong Kong include a 10.35-carat Colombian emerald and diamond ring (estimate: $870,000 - $1.2 million) and a pair of Colombian emerald and diamond earrings (estimate: $700,000 - $960,000). The emeralds featured in the earrings weigh 7.03 carats and 6.92 carats, respectively.



The auction will take place on May 27 during Hong Kong Luxury Week at Christie’s Asia Pacific headquarters at The Henderson, a 36-story state-of-the-art office tower that opened in 2024. The featured jewelry will be exhibited in Taipei, Bangkok, Geneva, Beijing and Shanghai before returning to Hong Kong for the sale.

Credits: Images courtesy of Christie's Images Ltd. 2025.

The Los Angeles Dodgers received their 2024 World Series Champion rings during an on-field ceremony prior to the team's opening day contest against the Detroit Tigers on Friday. Crafted in 14-karat yellow gold and teeming with white diamonds and blue sapphires, the rings also contain an unexpected surprise.



A special hinge mechanism on the top of the rings swings open to reveal a detailed replica of the Dodger Stadium along with an oval swatch harvested from the actual bases used during the 2024 World Series.



The impressive rings honor the team’s historic 98-win regular season, which culminated in a decisive victory over the New York Yankees in five games. It was the Dodgers' eighth title in the storied franchise's 142-year history.



The ring top features the iconic LA logo crafted from 17 custom-cut sapphires and surrounded with 47 diamonds. Encircling the logo is a sunburst shape that represents the sunny climate of Los Angeles and features 34 sapphires.

On both the left and right sides of the ring top are four large round diamonds, symbolizing the team's eight World Championship titles. An additional 20 diamonds are set along the sides.

Adorning the top and bottom of the ring top is the Dodgers 2024 title, WORLD CHAMPIONS, set with 53 white diamonds.

Completing the top and bottom edges of the ring are eight princess-cut sapphires. An additional 108 diamonds cascade from the ring top down the edges of the ring, creating a border around the side panels.

The left side of the ring features the recipient’s name rendered in yellow gold. Below the name, is a row of 14 princess-cut sapphires, and below the sapphires is the iconic Dodger Stadium sign displaying the player jersey number set in diamonds. One palm tree on each side of the sign gives the ring a distinctively LA vibe. Completing the left side of the ring is the Major League Baseball logo.

The right side of the ring displays the words LOS ANGELES, which pays homage to the home of the Dodgers since 1958. Below, a row of 14 princess-cut sapphires sit atop the championship year date, 2024, rendered with 29 white diamonds. More palm trees and the Dodgers logo complete the right side.

The innovative hinge mechanism opens to reveal a representation of the Commissioner’s Trophy emerging from the field at Dodger Stadium. A single diamond at the pinnacle of the trophy represents the 2024 World Series victory. Eight diamonds wrapping the outfield represent each of the team’s World Series titles. Banners for the years 1883 and 2024 mark the franchise’s 142 seasons.

On the opposite side of the hinged interior the oval swatch is embossed with the Dodgers/LA logo. Encircling the swatch are 34 sapphires honoring Dodgers pitcher Fernando Valenzuela, who wore that number and died just days before the 2024 World Series began.

Each player's unique signature is inscribed on the interior palm of the ring. Completing the outer palm is a row of five diamonds, representing the five-run deficit the Dodgers overcame against the Yankees to win the decisive Game 5 of the World Series.

Credits: Images courtesy of Jostens.

Welcome to Music Friday when we bring you fabulous songs with jewelry, gemstones or precious metals in the title or lyrics. Today, Aussie songstress Kylie Minogue explores the themes of ageism, empowerment and self-worth in her single, "Golden."



She sings, "We're not young and we're not old / We're the stories not yet told / Won't be bought and can't be sold / We are golden."

Released on her 50th birthday in May of 2018, "Golden" reflects Minogue's response to reporters' unrelenting questions about her age.

“This year, I’ll be fifty. And I get it. I get the interest, but I don’t know how to answer it," she told muumuse.com just ahead of the single's release. "And that line ["We're not young and we're not old"], for my personal satisfaction, says it as succinctly as possible. We can’t be anyone else; we can’t be younger or older than we are; we can only be ourselves. We’re golden. And the album title, Golden, reflects all of this."

She continued, "I liked the idea of everyone being golden, shining in their own way. The sun shines in daylight, the moon shines in darkness. Wherever we are in life, we are still golden.”

When Minogue sings, "stay golden," she's encouraging her listeners to remain positive and true to themselves while preserving a youthful, kindhearted spirit despite life's hardships.

And Minogue has overcome her share of challenges.

The singer was diagnosed with breast cancer in May 2005, resulting in the cancellation of the Australian leg of “Showgirl: The Greatest Hits” tour. She subsequently underwent successful surgery and radiotherapy, and resumed her touring schedule in November 2006 after being declared cancer-free.

Written by Minogue, Lindsay Rimes, Liz Rose and Steve McEwan, "Golden" is the title track of Minogue's 14th studio album. Minogue said the country-tinged song was inspired by her two-week visit to Nashville, a trip that she said has had a "profound" effect on the story-telling approach to her music.

Born Kylie Ann Minogue in 1968, the singer-songwriter began her career as a child actress on an Australian television series. In 1987, her breakout cover of the 1963 hit, “The Loco-Motion,” spent seven weeks at #1 on the Australian singles chart and became the best-selling Aussie single of the 1980s.

To date, Minogue has sold 80 million records worldwide, making her the highest-selling Australian-born solo artist of all time. She has earned numerous awards, including two Grammys, four Brit Awards, 18 ARIA (Australian Recording Industry Association) Music Awards and three MTV Video Music Awards.

Please check out the video of Minogue’s live performance of “Golden” during her Golden Tour in 2018. The lyrics are below if you’d like to sing along…

"Golden"
Written by Kylie Minogue, Lindsay Rimes, Liz Rose and Steve McEwan. Performed by Kylie Minogue.

Your feet move just like a dancer
Your soul beats just like a drum
Tomorrow has all the answers
Today says we've just begun

Don't you feel the sun on your face?
Hopeful hearts of the human race
Shining down from above

We're golden
Burn like the stars
Stay golden
Straight from the heart

We're the voice that'll never give in
Getting knocked down back up again
We're golden
Golden
That's who we are

Live your life like you're stealing
Every little moment in time
Infinity goes on forever
Lay your life on the line

Don't you feel the sun on your face?
Hopeful hearts of the human race
Wrapped in the arms of love

We're golden
Burn like the stars
Stay golden
Straight from the heart yeah

We're the voice that'll never give in
Getting knocked down back up again
We're golden golden
Golden
That's who we are

We're not young and we're not old
We're the stories not yet told
Won't be bought and can't be sold
We are golden

We're golden, golden
Burn like the stars
Stay golden, golden
Straight from the heart, yeah

We're the voice that'll never give in
Getting knocked down back up again
We're golden
Golden
That's who we are

Ahhhhh golden



Credits: Screen capture via YouTube / Kylie Minogue.

Leveraging an environment free from Earth's atmospheric contaminants, British tech company Space Forge aims to develop "perfect" diamond crystals in space.



By operating in space, Space Forge can grow diamonds under optimal conditions. Weightlessness provides for larger, perfect crystal formation, while near-zero temperatures allow for ultra-fast curing and operating in a vacuum eliminates contamination concerns.

A Space Forge spokesman told CBS News London that the growing chamber is essentially a "very fancy microwave."

"We put gases in, turn the microwave on, and we grow a crystal of material. And the crystal that we're growing… is [a diamond]," he said. "The advantage that we have is that, rather than doing that on the ground, we're actually making that material in space, where the conditions of no gravity and no atmosphere are perfect for that material."

Space Forge is promoting its ultra-pure diamonds for high-tech applications, such as heat conductors for electric vehicles and telecommunications. So far, the idea of space diamonds for jewelry is not on the company's radar.

Space Forge is aiming to prove the concept of in-orbit manufacturing as a new economy. The company's cosmic gem mission is set to launch from the US next month.

To ensure that the diamond crystals get back to Earth safely, the engineers at Space Forge designed an origami-style heat shield called Pridwen (named after King Arthur's shield) that intricately unfolds during reentry through the Earth's atmosphere.

Credit: Fanciful depiction of Space Forge diamond-growing operation in space by The Jeweler Blog using using ChatGPT and DALL-E 3.

What do the Uncle Sam Diamond and the Subway sandwich chain have in common? They both owe a world of gratitude to Dr. Peter Buck.



In June of 2022, the Smithsonian’s National Museum of Natural History unveiled the “Great American Diamonds” exhibit, highlighting four of the most stunning diamonds ever found in the United States. The headliner of the group was the Uncle Sam Diamond, a 12.4-carat emerald-cut stone fashioned from the largest uncut American diamond ever discovered.

The way the Smithsonian obtained the stone was through the generosity of Buck, who was not only a longstanding member of the Smithsonian National Museum of Natural History’s Advisory Board, but also the co-founder of 37,000-store Subway chain.

Dr. Jeffrey Post in his book, Unearthed, emphasized how Buck pounced on the opportunity to acquire the Uncle Sam Diamond after it has been out of the public eye for more than 50 years.

"He immediately decided that the Uncle Sam Diamond was a national treasure that should be available for all to see," he wrote, "and he purchased it for the Smithsonian National Gem Collection in 2019."

A nuclear physicist by trade, Buck is famous for making one of the most brilliant investments in US history. In 1965, at the age of 35, Buck loaned $1,000 to his family friend, Fred DeLuca, so he could open a sandwich shop. That shop was intended to help the 18-year-old DeLuca pay for college at the University of Bridgeport in Connecticut. DeLuca honored his benefactor by naming the shop “Pete’s Super Submarines.” That single store has since grown into the Subway sandwich chain, with worldwide sales reaching nearly $10 billion.

The near-flawless 12.4-carat pinkish-brown Uncle Sam Diamond was cut from a crystal weighing a whopping 40.23 carats. The rough gem was discovered in 1924 at the Prairie Creek mine (now known as Crater of Diamonds State Park), making it the largest faceted diamond ever discovered in the Arkansas mine.

The Uncle Sam Diamond embarked on a 98-year winding path until it finally settled into its display at the Janet Annenberg Hooker Hall of Geology, Gems and Minerals at the National Museum of National History in Washington, DC.

According to Post, the retired Curator of the National Gem and Mineral Collection at the Smithsonian Institute, the Uncle Sam Diamond in its original rough form was acquired from Arkansas Diamond Company shareholder Tomas Cochran by Schenck & Van Haelen of New York, a cutter that specialized in Arkansas diamonds.

Ernest G.H. Schenck cut the 40-plus-carat rough gem into a 14.34-carat parallelogram, and then recut it into a more traditional 12.42-carat emerald-cut gem to improve its overall brilliance. Boston jeweler Sydney DeYoung bought the stone from Schenck's estate in 1955 and then sold it about five years later to B. Beryl Peikin of Peikin Jewelers of Fifth Avenue, NY.

When Peikin passed away in 1988, the famous diamond (now set in a ring with two smaller Arkansas-sourced diamonds) remained in the possession of his wife until she passed at the age of 102. Jeweler DeYoung became the next owner, just briefly, until Buck proposed to take the gem to Washington for all to see.

Although he purchased the Uncle Sam Diamond in 2019, he would never get to see the “Great American Diamonds” exhibit. He passed away in November 2021, just five months ahead of the exhibit's unveiling.

Credit: Photo by James D. Tiller / Smithsonian.

Sometimes the best things in life are worth waiting for. That's certainly the sentiment of Tallulah Willis, who turned to Instagram on Saturday to gush over her "warm, depthful, ancient" engagement ring, which finally arrived three months after she accepted a marriage proposal and stand-in ring from musician Justin Acee.



The official ring features an antique 4.03-carat "honey champagne" diamond in a chunky gold setting reminiscent of an Ancient Greek vase.



"It reminds me of amphora, the way shoulders are, which is that very beautiful Greek vase, very femme, very beautiful," the 31-year-old daughter of Demi Moore and Bruce Willis, wrote in an Instagram post. "I love imbuing an item or an object or a piece or a sliver of something with magic, because it’s just so beautiful."



The old mine-cut diamond, which is secured in a bezel setting, sports a cushiony shape that was most popular during the Georgian and Victorian eras, roughly from the early 18th to the late 19th century.

“Never knew a ring could encapsulate a love so perfectly,” Willis noted. “Warm, depthful, ancient."

Willis also gave a shoutout to the New York-based designer, Karina Noel, who helped her design the ring — as well as her new fiancé.

"I am blown away thank you @karinanoel - our design come to life is extraordinary - more photos to come I’m currently caught up getting to know her!" she exclaimed, adding, "I choose you everyday my love @justinacee ~~I cannot wait to be your wife."

On the designer's Instagram page, Noel reflected on her collaboration with Willis.

"Tallulah look what we created!!" she wrote. "What a special journey working on this ring with you, and seeing the way it reflects your relationship with Justin is just incredible. That antique honey diamond has such a quiet depth to it, like it’s always held a story…we knew it. And that setting is the perfect home for her. Deeply, deeply grateful to be part of it."

A ring with an ancient vibe was also favored by three-time Grammy winner Dua Lipa. Back in early February, the singer treated her 87 million Instagram followers to a closeup view of an engagement ring from beau Callum Turner. The ring was described as Etruscan- or gypsy-inspired, with a 2-to-2.5-carat round center diamond in a half-bezel setting on a chunky yellow gold band.

A half-bezel setting is a jewelry design where only half of the gemstone is secured by a metal rim, essentially covering the sides of the stone while leaving the top and bottom exposed. This setting allows more light to reach the gem while still providing security with the bezel style.

Credits: Tallulah Willis image and ring selfies via instagram / buuski. Ring closeup via Instagram / karinanoel.

"The Mediterranean Blue," a 10.03-carat Fancy Vivid Blue diamond, is expected to fetch upwards of $20 million as the headliner of Sotheby’s High Jewelry Sale on May 13 in Geneva.



The stone’s exquisite cushion shape, paired with its exceptional size, clarity and saturation, places it in rarefied territory among the world’s most celebrated blue diamonds.

That elite club includes the 15.1-carat “De Beers Cullinan Blue” ($57.5 million, Sotheby’s Hong Kong, 2022), the 14.6-carat “Oppenheimer Blue” ($57.5 million, Christie’s Geneva, 2016) and the 12.03-carat “Blue Moon of Josephine” ($48.5 million, Sotheby’s Geneva, 2015).



In addition to receiving the highest possible color grading for a blue diamond from the Gemological Institute of America (GIA), The Mediterranean Blue has been found to be Type IIb, a quality level that represents less than 0.5% of all diamonds.

The Mediterranean Blue was crafted from a 31.94-carat rough diamond sourced at the Cullinan mine in South Africa in 2023. After a meticulous planning and cutting process lasting six months, The Mediterranean Blue was faceted into a cushion modified brilliant, a shape that lends a soft, refined look, while the skillfully positioned triangular and kite-shaped facets – characteristic of the brilliant cut – reflect light to create the captivating sparkle that makes this diamond come to life.

The diamond will be unveiled April 8 during a special exhibition hosted at the Bassam Freiha Art Foundation, a non-profit institution on Abu Dhabi’s landmark Saadiyat Island Cultural District. After that introduction, The Mediterranean Blue will be showcased in Tapei, Hong Kong and New York before its exhibition and sale in Geneva.

“The Mediterranean Blue represents one of nature’s rarest gems," noted Quig Bruning, Sotheby’s Head of Jewelry, Americas & EMEA. "Any vivid blue diamond is a discovery worth celebrating, but one as entrancing as this, particularly being over 10 carats, is a newsworthy event."

According to Sotheby's, only 0.3% of diamonds display a color that would be described as predominately blue among all diamonds submitted to GIA annually and, of those, only a small number are rated Fancy Vivid weighing 10 carats or more.

A fabulous fluke of nature, a blue diamond owes its color to the random presence of boron within the diamond’s carbon structure. Scientists believe that blue diamonds form about 400 miles below the surface, four times deeper than about 99 percent of all other diamonds.

Credits: Images courtesy of Sotheby's.

Welcome to Music Friday when we bring you inspirational songs with jewelry, gemstones or precious metals in the title or lyrics. Today, the talented members of the One Voice Children’s Choir dazzle us with their interpretation of Rihanna’s “Diamonds.” The choir's official video at the end of this post has been viewed on YouTube more than 247 million times.



In the song, the youngsters inspire their peers to “shine bright like a diamond” and embrace the wonders that life has to offer.

They sing, “Find light in the beautiful sea, I choose to be happy / You and I, you and I, we’re like diamonds in the sky / You’re a shooting star I see, a vision of beauty / When you're near me, I’m alive / We’re like diamonds in the sky.”

Ranging in age from five to 18, the One Voice singers are directed by Masa Fukuda. The group was originally assembled by Fukuda to perform at the 2002 Winter Olympics in Utah, but remained together after the sporting event. The group has about 180 members and performs 50 to 70 times each year.

The group competed during Season 9 of NBC’s America’s Got Talent in 2014 and reached the quarter finals. Earlier in the competition, judge Howard Stern told the young contestants that they were "gold," but Howie Mandel was not as impressed.

“They are gold,” Mandel agreed. “I’m looking for a diamond.”

Despite Mandel’s thumbs-down verdict, Stern, Mel B and Heidi Klum voted in favor of the group and they moved on in the competition. The choir director’s decision to perform “Diamonds” and produce the companion video was in direct response to Mandel’s criticism.

The group's YouTube channel boasts 4.93 million subscribers and more than 1.1 billion views. "Diamonds" remains the group's most popular video.

Rihanna scored her 12th #1 single with “Diamonds” in 2012. In fact, the song topped the charts in 20 countries and became a Diamond-certified record in April 2024 after its sales surpassed 10 million worldwide. It is one of the best-selling singles in music history. Rihanna's official video of "Diamonds" has been viewed an extraordinary 2.4 billion times.

Rihanna characterized the song as “happy and hippie.”

“It’s hopeful. It gives me a great feeling when I listen to it,” she said during an iHeartRadio festival in Las Vegas. “The lyrics are hopeful and positive. It’s about love and the gears are different than what people will expect.”

The song was written by Sia Furler with Benjamin Levin, Mikkel S. Eriksen and Tor Erik Hermansen. Sia told New York Times Magazine that she came up with the lyrics for “Diamonds” in just 14 minutes.

According to SongFacts.com, “Diamonds” became the third diamond-titled song to score a #1 chart appearance. The others were Gary Lewis and the Playboys’ “This Diamond Ring” (1965) and Elton John’s “Lucy In The Sky With Diamonds” (1974).

Please check out the video of the One Voice Children’s Choir performing “Diamonds.” The lyrics are below if you’d like to sing along…

“Diamonds”
Written by Sia Furler, Benjamin Levin, Mikkel S. Eriksen and Tor Erik Hermansen. Performed by the One Voice Children’s Choir.

Shine bright like a diamond
Shine bright like a diamond

Find light in the beautiful sea, I choose to be happy
You and I, you and I, we’re like diamonds in the sky
You’re a shooting star I see, a vision of beauty
When you're near me, I’m alive
We’re like diamonds in the sky

I knew that we’d become one right away
Oh, right away
At first sight I felt the energy of sunrays
I saw the life inside your eyes

So shine bright tonight,
You and I
We’re beautiful like diamonds in the sky
Eye to eye,
So alive
We’re beautiful like diamonds in the sky

Shine bright like a diamond
Shine bright like a diamond
Shining bright like a diamond
We’re beautiful like diamonds in the sky

Shine bright like a diamond
Shine bright like a diamond
Shining bright like a diamond
We’re beautiful like diamonds in the sky



Credit: Screen capture via YouTube / One Voice Children's Choir.

In modern times, diamond-tipped tools, such as drill bits, burrs and saw blades, are used to carve and shape gemstones due to their exceptional hardness and ability to cut through just about any material.



But, did you know that ancient jewelers knew that secret more than 2,000 years ago?

According to a new study published in the journal Archaeological and Anthropological Sciences, the ancient nomadic tribes that traversed Central Asia used diamond drills to perforate gemstones when crafting necklaces, bracelets and pendants.

The researchers employed Scanning Electron Microscopy (SEM) to study the interior drill hole surface of 51 stone beads recovered from the ancient Rabat Cemetery in Uzbekistan. All of the bead varieties — including carnelian, agate, and garnet — rated a 6.5 to 7 on the Mohs hardness scale. Diamond, by comparison, carries a Mohs rating of 10 and is the hardest naturally occurring material known to man.

The burial site, in the historic region of Bactria (encompassing parts of modern-day Afghanistan, Uzbekistan and Tajikistan) was used by the nomadic Yuezhi people from the second century BC to the first century AD.

Of the 51 beads studied, 41 presented markings associated with the use of a diamond drill. The researchers noted that the Yuezhi used two distinctive types of diamond drills to perforate gemstones. The ancient jewelers used a single diamond drill to start the hole, and then switched to “a narrower double diamond drill with two symmetrically placed diamonds at the tip of the drill” to finish their work.

There was also evidence that the artisans drilled holes from both sides of the same bead, with the holes converging in the middle.

The researchers pointed out that there are significant differences between the diamond drilling techniques used in Bactria and those seen on similar beads from the Indus Valley (modern-day Pakistan, northwest India and northeast Afghanistan). This finding suggests that the drilled beads were manufactured locally and not imported from the Indus region.

Other ancient civilizations successfully drilled holes in gemstones without the assistance of diamonds. Instead they used a combination of tools and abrasives, including copper tubes, sand and possibly other materials, such as quartz or corundum, often with the aid of a bow drill or similar rotating mechanisms.

Credit: AI-generated gem market image by The Jeweler Blog using ChatGPT and DALL-E 3.