Skip to main content

18 Carat Diamond

to
3,368
33,023
27,667
14,971
9,542
2,603
32,997
6,615
3,962
2,689
2,486
37
899
9,137
23,970
722
701
614
464
277
577
542
572
791
871
20
23,646
10,092
329
11857
2989
2252
1918
1532
to
13
12
2
1,804
670
595
531
414
8,920
8,253
2,342
990
922
686
416
215
96
58
53
30
28
16
9
3
33,840
227
16,844
11,627
Sort By
Cellini 18 Karat Gold Necklace with 37.77 Carat Rubelite 10.43 Carat Diamonds
By Cellini
Located in New York, NY
connectors. The total length of the necklace is 17.5" long. 22 Rubelites = 37.77 carats Round Diamonds
Category

Early 2000s Contemporary Link Necklaces

Materials

Diamond, Rubelite, 18k Gold, White Gold

Natural Diamond 0.51 carats 18 Karat White Gold Chain Pendant Necklace
Located in Antwerpen, BE
White Gold Weight: 2.13 Grams Gemstone: Natural Diamonds Total Carat Weight: 0.51 cts Numbers of
Category

2010s Belgian Modern Chain Necklaces

Materials

Diamond, 18k Gold, White Gold

Art Deco Diamond 18 Carat Gold Full Eternity Band
Located in Chipping Campden, GB
An exquisite Art Deco eternity band fully set with stunning white diamonds and modelled in 18 Carat
Category

Vintage 1910s Unknown Art Deco Band Rings

Materials

Diamond, 18k Gold, Gold

Vintage Diamond and 18 Carat White Gold Eternity Ring
Located in Chipping Campden, GB
band is modelled in 18 carat white gold. The band itself has wonderful engraving all the way around
Category

Vintage 1910s British Art Deco Wedding Rings

Materials

Diamond, White Gold

18 Karat Yellow Gold Janet floating Diamond Ring 1/5 Carat
Located in San Francisco, CA
One row of round brilliant diamonds floats between two gleaming metal bands. (1/5 total carat
Category

21st Century and Contemporary American Band Rings

Materials

Diamond, Yellow Gold

18 Karat Rose Gold Janet Floating Diamond Ring 1/5 Carat
Located in San Francisco, CA
One row of round brilliant diamonds floats between two gleaming metal bands. (1/5 total carat
Category

21st Century and Contemporary American Band Rings

Materials

Diamond, Rose Gold

18 Karat White Gold Janet Floating Diamond Ring 1/5 Carat
Located in San Francisco, CA
One row of round brilliant diamonds floats between two gleaming metal bands. (1/5 total carat
Category

21st Century and Contemporary American Band Rings

Materials

Diamond, White Gold

Edwardian Diamond Five-Stone 18 Carat Gold Ring
Located in Chipping Campden, GB
Five glistening old mine cut diamonds sit fabulously within a simple setting modelled in 18ct gold
Category

Antique Early 1900s British Edwardian More Rings

Materials

Diamond, Gold

Crop Farr Diamond and 18 Carat Gold Ring
Located in Chipping Campden, GB
This Crop & Farr ring holds 8 diamonds which total 32pts. The chunky 18carat gold is textured and
Category

Vintage 1970s British Cluster Rings

Materials

Diamond, Gold

0.81 Carat Diamond/0.92 Carat Blue Sapphire 18 Karat Gold Heart Split Shank Ring
By Sebastian Bernard
Located in Los Angeles, CA
Weight 0.92 Ct) surrounded by a Channel set Halo of diamonds and channel set split shank with total
Category

2010s American Contemporary Fashion Rings

Materials

Diamond, Blue Sapphire, 18k Gold

Edwardian Diamond Five-Stone 18 Carat Gold Ring
Located in Chipping Campden, GB
Five glistening diamonds sit fabulously within a simple setting modelled in 18ct gold. The diamonds
Category

Antique Early 1900s British Edwardian More Rings

Materials

Diamond, Gold

2.61ct Aquamarine and Diamond 18 Carat White Gold Cluster Engagement Ring
Located in London, GB
beautiful cluster is sat 9.9mm proud of the finger and mounted atop a delicate 1.6mm 18 carat white gold
Category

Vintage 1960s European Cluster Rings

Materials

Aquamarine, Diamond, 18k Gold, White Gold

Natural Diamond 1.85 carats 18 Karat White Gold Drop Dangler Earrings
Located in Antwerpen, BE
1.85 carats of baguette and round-cut diamonds, delicately set in a mesmerizing cluster design. The
Category

2010s Belgian Modern Dangle Earrings

Materials

Diamond, 18k Gold, White Gold

Certified 1.51 Carats Blood Pigeon Ruby Diamonds Yellow Gold 18 Carats Ring
Located in Vannes, FR
Certified 1.51 Carats Blood Pigeon Ruby Diamonds Yellow Gold 18 Carats Cocktail Ring This ring is
Category

21st Century and Contemporary French Contemporary Cocktail Rings

Materials

Diamond, Ruby, Gold, 18k Gold, Yellow Gold

Diamond 18 Karat White Gold Drop Earrings, 5.96 Carats
Located in London, GB
A pair of diamond drop earrings, with an openwork scrolled frame, with trefoil flowers, set with
Category

2010s British Modern Drop Earrings

Materials

Diamond, 18k Gold, White Gold

1.04ct Ruby and Diamond 18 Carat White Gold Twisted Dress Ring
Located in London, GB
This wonderful 18 carat white gold dress ring is designed as a twisted tridimensional ribbon inlaid
Category

1990s Unknown Modern Cocktail Rings

Materials

Diamond, White Diamond, Ruby, Gold, 18k Gold, White Gold

Picchiotti 18 Karat Gold 4.58 Carat Sapphire and 2.32 Carat Diamond Earrings
By Picchiotti
Located in New York, NY
sapphires and round brilliant diamonds, set in 18 karat yellow gold. Clip on Earrings, can be adjusted to
Category

1990s Italian Contemporary Clip-on Earrings

Materials

Diamond, Sapphire, 18k Gold, Yellow Gold

Ring with Emerald 3.71 Carats and 18 Carat White Gold with Diamonds
Located in Paris, FR
18-karat yellow and white gold diamond and emerald ring 3.71 carats Ring in 18-carat white gold
Category

Early 2000s French Cocktail Rings

Materials

Diamond, Emerald, 18k Gold, White Gold

95.42 Carat Diamond 18 Karat Gold Tassel Necklace
By Meghna Jewels
Located in Hoffman Estate, IL
A stunning tassel necklace is handmade in 18K gold and set in 95.42 carats of glimmering diamonds
Category

21st Century and Contemporary Unknown Artisan Beaded Necklaces

Materials

Diamond, 18k Gold, Gold

Straight Line Diamond Tennis Necklace in 18K White Gold, 5.25 Carats, 18"
Located in New York, NY
showcases 5.25 carats of natural round brilliant diamonds. Each diamond is meticulously set to create a
Category

2010s American Modern Chain Necklaces

Materials

Diamond, White Gold, 18k Gold

GIA Certified 2.39 Carat Emerald Diamond 18 Karat White Gold Ring
By Roshe Jewels
Located in Los Angeles, CA
surrounded by 48 Round Cut Diamonds weighing 1.22 carats (Clarity: VS, Color: H). The total carat weight is
Category

21st Century and Contemporary American Modern Cocktail Rings

Materials

Diamond, Emerald, 18k Gold, White Gold

Edwardian Diamond and 18 Carat Gold Three Stone Ring
Located in Chipping Campden, GB
This edwardian diamond three stone holds three diamonds totalling 75pts and modelled in 18 carat
Category

Antique Early 1900s British Edwardian Three-Stone Rings

Materials

Diamond, Gold, 18k Gold

2.88 Carat Emerald Diamond Halo Ring in 18 Karat White Gold
Located in Great Neck, NY
Oval emerald weighing 2.88 carats Diamonds weighing .69 cts Halo style ring. Zambian origin 18
Category

2010s American Modern Cocktail Rings

Materials

Diamond, Emerald, 18k Gold, White Gold

Emilio Jewelry 18 Carat Emerald Cut Sapphire Diamond Ring
By Emilio!
Located in New York, NY
in high end jewels. An incredible Emerald cut center sapphire almost 18 carats, sits in the center
Category

21st Century and Contemporary Three-Stone Rings

Materials

Diamond, Sapphire

18 Karat White Gold 0.10 Carat Diamond Solitaire Necklace
By Campanelli Pear
Located in Troy, MI
is the necklace for you- crafted from 18 karat white gold with one round brilliant diamond = 0.10
Category

21st Century and Contemporary American Contemporary Pendant Necklaces

Materials

Diamond, 18k Gold, White Gold

Natural Diamond Band 0.26 carats 18 Karats White Gold Anniversary Band
Located in Antwerpen, BE
At the heart of the ring lies a row of round diamonds totaling 0.26 carats, each diamond
Category

2010s Belgian Modern Band Rings

Materials

Diamond, 18k Gold, White Gold

1.58 Carat Emerald and Diamond 18 Karat White Gold Engagement Ring
By Roshe Jewels
Located in Los Angeles, CA
center oval cut Emerald is 1.00 Carat and has a Halo of 62 Round Cut Diamonds weighing 0.58 Carats. The
Category

21st Century and Contemporary American Contemporary Engagement Rings

Materials

Diamond, Emerald, 18k Gold, White Gold

1.80 Carat Diamond 18 Karat Gold Bangle Bracelet
By Meghna Jewels
Located in Hoffman Estate, IL
A stunning bangle bracelet handmade in 18K gold and set in 1.80 carats of sparkling diamonds. Wear
Category

21st Century and Contemporary Unknown Artisan Modern Bracelets

Materials

Diamond, Gold, 18k Gold

Vintage Aquamarine and Diamond 18 Carat Gold Solitaire Ring
Located in Chipping Campden, GB
approx 80pts and the diamonds total 42pts. The ring is modelled in 18 carat gold. Ring Size: K 1/2 or 5
Category

Vintage 1980s British Cocktail Rings

Materials

Aquamarine, Diamond, Gold, 18k Gold

Vintage Diamond and 18 Carat Gold Cluster Panel Ring
Located in Chipping Campden, GB
. The ring is modelled in 18 Carat gold and the stones are set in platinum. Size: N 1/2 or 7 Cluster
Category

Vintage 1970s British More Rings

Materials

Diamond, Gold, Platinum

2.22 Carat Orange Sapphire Diamond 18 Karat Rose Gold Bridal Ring
By Roshe Jewels
Located in Los Angeles, CA
Sapphires that weigh 0.50 carats and 28 Round Cut Diamonds that weigh 0.47 carats (Clarity: VS2, Color: H
Category

21st Century and Contemporary American Contemporary Cocktail Rings

Materials

Sapphire, Diamond, Rose Gold, 14k Gold

Natural Diamond 1.18 carats 18 Karat White Gold Flower Statement Ring
Located in Antwerpen, BE
opulent appeal. With a total diamond weight of 1.18 carats, The diamonds in this ring are 100% conflict
Category

2010s Belgian Modern Cocktail Rings

Materials

Diamond, 18k Gold, White Gold

Modern Diamond an 18 Carat Gold Solitaire Ring
Located in Chipping Campden, GB
The design of the ring is so simple and beautiful. The diamond measures 30pts and is set in
Category

Vintage 1980s British Modern Solitaire Rings

Materials

Diamond, Gold

18-Carat Yellow Gold Stud Earrings with Natural Diamonds
Located in Berlin, DE
These stylish stud earrings made from high-quality 18-carat 750 yellow gold combine classic
Category

21st Century and Contemporary Unknown Modern Clip-on Earrings

Materials

Diamond, 18k Gold, Yellow Gold

Emerald Diamond Art Deco Style Necklace 18 Karat White Gold .80 Carat Diamond
By Five Star Jewelry
Located in Austin, TX
! 18K White Gold 0.82 Carat Total Diamond Weight 16 Inches Long
Category

21st Century and Contemporary Art Deco Pendant Necklaces

Materials

Diamond, Gold, 18k Gold, White Gold

18 Karat Rose Gold Star Station Diamond Necklace 1/5 Carat
Located in San Francisco, CA
This delicate necklace features three (3) Star-shaped diamond pendants evenly stationed between six
Category

21st Century and Contemporary American More Necklaces

Materials

Diamond, Rose Gold

18 Karat White Gold Star Station Diamond Necklace 1/5 Carat
Located in San Francisco, CA
This delicate necklace features three (3) Star-shaped diamond pendants evenly stationed between six
Category

21st Century and Contemporary American More Necklaces

Materials

Diamond, White Gold

18 Karat Yellow Gold Star Station Diamond Necklace 1/5 Carat
Located in San Francisco, CA
This delicate necklace features three (3) Star-shaped diamond pendants evenly stationed between six
Category

21st Century and Contemporary American More Necklaces

Materials

Diamond, Yellow Gold

18 Karat White Gold Hoop Insideout Diamond Earrings 4/5 Carat
Located in San Francisco, CA
This hoop earring features round brilliant diamonds micro-prong set. The diamonds are set
Category

21st Century and Contemporary American Hoop Earrings

Materials

Diamond, White Gold

18 Karat Yellow Gold Hoop Insideout Diamond Earrings 4/5 Carat
Located in San Francisco, CA
This hoop earring features round brilliant diamonds micro-prong set. The diamonds are set
Category

21st Century and Contemporary American Hoop Earrings

Materials

Diamond, Yellow Gold

18 Karat Rose Gold Hoop Insideout Diamond Earrings 4/5 Carat
Located in San Francisco, CA
This hoop earring features round brilliant diamonds micro-prong set. The diamonds are set
Category

21st Century and Contemporary American Hoop Earrings

Materials

Diamond, Rose Gold

Natural Diamond Ring 0.27 carats 18 Karat White Gold Engagement Ring
Located in Antwerpen, BE
: Natural Diamonds Shape: Round Brilliant Diamond Total Carat Weight: 0.27 cts Number of Gemstones: 18
Category

2010s Belgian Modern Engagement Rings

Materials

Diamond, 18k Gold, White Gold

18 Karat Yellow Gold Hoop Insideout Diamond Earrings 1/2 Carat
Located in San Francisco, CA
This hoop earring features round brilliant diamonds micro-prong set. The diamonds are set
Category

21st Century and Contemporary American Hoop Earrings

Materials

Diamond, Yellow Gold

18 Karat Yellow Gold Hoop Insideout Diamond Earings 3/4 Carat
Located in San Francisco, CA
This hoop earring features round brilliant diamonds "U" shapes prong set. The diamonds are set
Category

21st Century and Contemporary American Hoop Earrings

Materials

Diamond, Yellow Gold

18 Karat Rose Gold Hoop Insideout Diamond Earrings 1/2 Carat
Located in San Francisco, CA
This hoop earring features round brilliant diamonds micro-prong set. The diamonds are set
Category

21st Century and Contemporary American Hoop Earrings

Materials

Diamond, Rose Gold

18 Karat White Gold Hoop Insideout Diamond Earrings 1/2 Carat
Located in San Francisco, CA
This hoop earring features round brilliant diamonds micro-prong set. The diamonds are set
Category

21st Century and Contemporary American Hoop Earrings

Materials

Diamond, White Gold

18 Karat Rose Gold Hoop Insideout Diamond Earings 3/4 Carat
Located in San Francisco, CA
This hoop earring features round brilliant diamonds "U" shapes prong set. The diamonds are set
Category

21st Century and Contemporary American Hoop Earrings

Materials

Diamond, Rose Gold

18 Karat White Gold Hoop Insideout Diamond Earings 3/4 Carat
Located in San Francisco, CA
This hoop earring features round brilliant diamonds "U" shapes prong set. The diamonds are set
Category

21st Century and Contemporary American Hoop Earrings

Materials

Diamond, White Gold

Vintage Diamond and 18 Carat Gold Cluster Ring
Located in Chipping Campden, GB
The intricate design of this ring is absolutely gorgeous. Its is adorned in diamonds and modelled
Category

Vintage 1950s British Modern Cluster Rings

Materials

Diamond, 18k Gold, Gold

18 Karat Rose Gold Butterfly Large Diamond Necklace 1/2 Carat
Located in San Francisco, CA
This delicate necklace features a 16 MMx16 MM Butterfly diamond pendent micro-prong-set stationed
Category

21st Century and Contemporary American More Necklaces

Materials

Diamond, Rose Gold

18 Karat White Gold Butterfly Large Diamond Necklace 1/2 Carat
Located in San Francisco, CA
This delicate necklace features a 16 MMx16 MM Butterfly diamond pendent micro-prong-set stationed
Category

21st Century and Contemporary American More Necklaces

Materials

Diamond, White Gold

18 Karat Yellow Gold Butterfly Large Diamond Necklace 1/2 Carat
Located in San Francisco, CA
This delicate necklace features a 16 MMx16 MM Butterfly diamond pendent micro-prong-set stationed
Category

21st Century and Contemporary American More Necklaces

Materials

Diamond, Yellow Gold

18 Karat Yellow Gold Dangling Halo Diamond Earrings 2/5 Carat
Located in San Francisco, CA
These elegant and delicate earrings feature round brilliant diamond micro prong-set in a retro halo
Category

21st Century and Contemporary American Dangle Earrings

Materials

Diamond, Yellow Gold

18 Karat White Gold Dangling Halo Diamond Earrings 2/5 Carat
Located in San Francisco, CA
These elegant and delicate earrings feature round brilliant diamond micro prong-set in a retro halo
Category

21st Century and Contemporary American Dangle Earrings

Materials

Diamond, White Gold

18 Karat Rose Gold Dangling Halo Diamond Earrings 2/5 Carat
Located in San Francisco, CA
These elegant and delicate earrings feature round brilliant diamond micro prong-set in a retro halo
Category

21st Century and Contemporary American Dangle Earrings

Materials

Diamond, Rose Gold

Sapphires Diamonds 18 Carat White Gold Modern Choker Necklace
By SCALA GIOIELLI
Located in Marcianise, IT
every facet. Brilliant-cut diamonds totaling 1.06 carats are set between the sapphires, adding a refined
Category

Early 2000s Italian Artisan Choker Necklaces

Materials

Diamond, Sapphire, 18k Gold, White Gold

18 Karat Rose Gold Bezel Hoop Diamond Earrings 1/3 Carat
Located in San Francisco, CA
This elegant hoop earring features an alternating in size round brilliant diamonds bezel set. The
Category

21st Century and Contemporary American Hoop Earrings

Materials

Diamond, Rose Gold

  • 1
  • ...
Get Updated with New Arrivals
Save "18 Carat Diamond", and we’ll notify you when there are new listings in this category.

18 Carat Diamond For Sale on 1stDibs

On 1stDibs, you can find the most appropriate 18 carat diamond for your needs in our varied inventory. Every item for sale was constructed with extraordinary care, often using Gold, 18k Gold and White Gold. Our collection of these items for sale includes 16174 vintage editions and 32669 modern creations to choose from as well. Finding the perfect 18 carat diamond may mean sifting through those created during different time periods — you can find an early version that dates to the 18th Century and a newer variation that were made as recently as the 21st Century. For this particular accessory, there are many different carat weights to choose from, but .5 Carat and 1 Carat versions are of considerable interest. Finding an appealing 18 carat diamond — no matter the origin — is easy, but Roman Malakov, Meghna Jewels and LB Exclusive each produced a popular version that is worth a look. A round cut version of this piece has appeal, but there are also oval cut and cushion cut versions for sale. If you’re browsing our inventory for a 18 carat diamond, you’ll find that many are available today for women, but there are still pieces to choose from for unisex and men.

How Much is a 18 Carat Diamond?

Prices for a 18 carat diamond can differ depending upon size, time period and other attributes — at 1stDibs, these accessories begin at $19 and can go as high as $135,979,328, while this accessory, on average, fetches $5,813.

Why Gold Shines in Jewelry Craftsmanship

Gold is the feel-good metal, the serotonin of jewelry. Wear vintage and antique gold necklaces, watches, gold bracelets or gold rings and you feel happy, you feel dressed, you feel, well, yourself. 

Gold, especially yellow gold, with its rich patina and ancient pedigree going back thousands of years, is the steady standby, the well-mannered metal of choice. Any discussion of this lustrous metal comes down to a basic truth: Gold is elementary, my dear. Gold jewelry that couples the mystique of the metal with superb design and craftsmanship achieves the status of an enduring classic. Many luxury houses have given us some of our most treasured and lasting examples of gold jewelry over the years.

Since its founding, in 1837, Tiffany Co. has built its reputation on its company jewelry as well as its coterie of boutique designers, which has included Jean Schlumberger, Donald Claflin, Angela Cummings and Elsa Peretti. There are numerous gold Tiffany classics worth citing. Some are accented with gemstones, but all stand out for their design and the workmanship displayed.

For the woman who prefers a minimalist look, the Tiffany Co. twist bangle (thin, slightly ovoid) is stylishly simple. For Cummings devotees, signature pieces feature hard stone inlay, such as her pairs of gold ear clips inlaid with black jade (a play on the classic Chanel black and tan), or bangles whose design recalls ocean waves, with undulating lines of lapis lazuli and mother-of-pearl. And just about any design by the great Jean Schlumberger is by definition a classic.

Even had he eschewed stones and diamonds, Southern-born David Webb would be hailed for the vast arsenal of heavy gold jewelry he designed. Gold, usually hammered or textured in some manner, defines great David Webb jewelry. The self-taught jeweler made very au courant pieces while drawing inspiration from ancient and out-of-the-way sources — East meets West in the commanding gold necklaces made by Webb in the early 1970s. The same could be said for his endlessly varied gold cuffs.

In Europe, many houses have given us gold jewelry that sets the highest standard for excellence, pieces that were highly sought after when they were made and continue to be so. 

Numerous designs from Cartier are homages to gold. There are the classic Trinity rings, necklaces and bracelets — trifectas of yellow, white and rose gold. As a testament to the power of love, consider the endurance of the Cartier Love bracelet.

Aldo Cipullo, Cartier’s top in-house designer from the late 1960s into the early ’70s, made history in 1969 with the Love bracelet. Cipullo frequently said that the Love bracelet was born of a sleepless night contemplating a love affair gone wrong and his realization that “the only remnants he possessed of the romance were memories.” He distilled the urge to keep a loved one close into a slim 18-karat gold bangle. 

BVLGARI and its coin jewelry, gemme nummarie, hit the jackpot when the line launched in the 1960s. The line has been perennially popular. BVLGARI coin jewelry features ancient Greek and Roman coins embedded in striking gold mounts, usually hung on thick link necklaces of varying lengths. In the 1970s, BVLGARI introduced the Tubogas line, most often made in yellow gold. The Tubogas watches are classics, and then there is the Serpenti, the house's outstanding snake-themed watches and bracelets.

A collection called Monete that incorporated the gold coins is one of several iconic BVLGARI lines that debuted in the 1970s and ’80s, catering to a new generation of empowered women. Just as designers like Halston and Yves Saint Laurent were popularizing fuss-free ready-to-wear fashion for women on the go, BVLGARI offered jewels to be lived in

Since Van Cleef Arpels opened its Place Vendôme doors in 1906, collection after collection of jewelry classics have enchanted the public. As predominantly expressed in a honeycomb of gold, there is the Ludo watch and accessories, circa the 1920s, and the golden Zip necklace, 1951, whose ingenious transformation of the traditional zipper was originally proposed by the Duchess of Windsor. Van Cleef's Alhambra, with its Moroccan motif, was introduced in 1968 and from the start its popularity pivoted on royalty and celebrity status. It remains one of VCA’s most popular and collected styles.

Mention must be made of Buccellati, whose name is synonymous with gold so finely spun that it suggests tapestry. The house’s many gold bracelets, typically embellished with a few or many diamonds, signified taste and distinction and are always in favor on the secondary market. Other important mid-20th-century houses known for their gold-themed jewelry include Hermès and Ilias Lalaounis.

Find a stunning collection of vintage and antique gold jewelry on 1stDibs.

The Legacy of Diamond in Jewelry Design

Antique diamond rings, diamond tiaras and dazzling vintage diamond earrings are on the wish lists of every lover of fine jewelry. And diamonds and diamond jewelry are primarily associated with storybook engagements and red-carpet grand entrances — indeed, this ultra-cherished gemstone has a dramatic history on its hands.

From “A Diamond Is Forever” to “Diamonds Are a Girl’s Best Friend,” pop culture has ingrained in our minds that diamonds are the most desired, the most lasting and the most valuable gemstone. But what makes the diamond so special? Each stone — whether it’s rubies, sapphires or another stone — is unique and important in its own right. April babies might claim diamonds for themselves, but just about everyone wants this kind of sparkle in their lives!

There are several factors that set diamonds apart from other stones, and these points are important to our gem education.

Diamonds are minerals. They are made up of almost entirely of carbon (carbon comprises 99.95 percent; the remainder consists of various trace elements). Diamonds are the hardest gemstones, ranking number 10 on the Mohs Hardness Scale. Even its name, diamond, is rooted in the Greek adamas, or unconquerable. The only object that can scratch a diamond is another diamond. Diamonds are formed deep within the earth at very high temperatures (1,652–2,372 degrees Fahrenheit at depths between 90 and 120 miles beneath the earth’s surface) and are carried up by volcanic activity. Diamonds are quite rare, according to the Gemological Institute of America, and only 30 percent of all the diamonds mined in the world are gem quality.

In the 1950s, the Gemological Institute of America developed the 4Cs grading system to classify diamonds: clarity, color, cut and carat weight. Not all diamonds are created equal (there are diamonds, and then there are diamonds). The value of the diamond depends on the clarity (flawless diamonds are very rare but a diamond's value decreases if there are many blemishes or inclusions), color (the less color the higher the grade), cut (how the diamond’s facets catch the light, certain cuts of diamonds show off the stone better than others) and carat weight (the bigger, the better).

When you start shopping for a diamond engagement ring, always prioritize the cut, which plays the largest role in the diamond's beauty (taking the time to clean your diamond ring at least every six months or so plays a role in maintaining said beauty). And on 1stDibs, a range of buying guides can be found for those in the market for antique engagement ringsvintage engagement rings or Art Deco engagement rings

Shop antique and vintage diamond rings, diamond necklaces and other extraordinary diamond jewelry on 1stDibs.  

Questions About 18 Carat Diamond
  • 1stDibs ExpertMarch 22, 2022
    A 24-carat diamond is a precious diamond gemstone that weighs 24 carats. One carat weighs 200 milligrams, meaning a 24-carat diamond weighs roughly 4.8 grams. That equates to roughly 0.17 ounces. On 1stDibs, shop a variety of diamond jewelry.
  • 1stDibs ExpertApril 5, 2022
    Yes, there are three-carat diamonds, and you can find them from a number of different jewelers and other retailers. Find an assortment of diamond jewelry from the world’s top sellers on 1stDibs.
  • 1stDibs ExpertNovember 6, 2023
    There is no hard-and-fast rule for how many carats a diamond necklace should be. On average, solitaire diamond necklaces range from 0.5 to 1 carat, but you can find pieces with larger and smaller stones. Tennis chains that feature continuous diamonds set into links usually have much higher total carat weights. For example, one might feature 60 individual diamonds, each 0.20 carats in size, for a total carat weight of 12.0 carats. Shop a wide range of diamond necklaces on 1stDibs.
  • 1stDibs ExpertApril 5, 2022
    A nine-carat diamond is considered rare and holds a premium price. Because of their rarity and size, nine-carat diamonds are a coveted choice for engagement rings. One of the most famous nine-carat diamond rings belongs to actress Kate Hudson, who has a nine-carat emerald cut diamond complemented with tapered baguettes on a platinum band. Shop a selection of diamond jewelry on 1stDibs.
  • 1stDibs ExpertSeptember 28, 2021
    An 8-carat diamond’s worth varies depending on the 4Cs of diamond quality – color, cut, clarity and carat. On an average an 8-carat diamond could cost you between $17,500 to $90,000. It is also likely that the price range per carat will be even broader. On 1stDibs, you can find a variety of 8-carat diamond jewelry from different periods and styles to choose from.
  • 1stDibs ExpertSeptember 28, 2021
    A 4-carat diamond’s worth varies depending on the 4Cs of diamond quality – color, cut, clarity and carat. On average, a 4-carat diamond could cost you between $8,400 to $71,500. It is also likely that the price range per carat will be even broader. On 1stDibs, you can find a variety of 4-carat diamond jewelry.
  • 1stDibs ExpertSeptember 28, 2021
    A 6-carat diamond’s worth varies depending on the 4Cs of diamond quality – color, cut, clarity and carat. On average, a 6-carat diamond could cost you between $15,000 to $80,000. It is also likely that the price range per carat will be even broader. On 1stDibs, you can find a variety of 6-carat diamond jewelry.
  • 1stDibs ExpertSeptember 28, 2021
    A 5-carat diamond’s worth varies depending on the 4Cs of diamond quality – color, cut, clarity and carat. On average, a 5-carat diamond could cost you between $9,600 to $67,500. It is also likely that the price range per carat will be even broader. On 1stDibs, you can find a variety of 5-carat diamond jewelry.
  • 1stDibs ExpertSeptember 28, 2021
    The minimum value of a 25-carat diamond ranges from $300 to $1,400. The prices change subject to the fluctuation of market factors. The value is defined based on the 4Cs — color, clarity, cut and carat weight. Shop antique, vintage and new diamond jewelry on 1stDibs.
  • 1stDibs ExpertFebruary 27, 2024
    Whether a 1.5-carat diamond is too big depends on the type of jewelry in question and your personal preferences. A single stud earring that is 1.5 carats is rather large and would cover the entire earlobe. In terms of rings, a 1.5-carat diamond is larger than average. Find a variety of diamond jewelry on 1stDibs.
  • 1stDibs ExpertFebruary 13, 2023
    Yes, a two-carat diamond is generally rarer than a smaller diamond, especially high-quality two-carat diamonds. When larger diamonds are found in nature, they usually have flaws. And prices per carat don’t increase as weight increases. A three-carat gem can be less valuable than a one-carat stone, for example, if all of the other attributes are of lesser quality in the larger diamond. Shop an assortment of diamond jewelry from some of the world’s top jewelers on 1stDibs.
  • 1stDibs ExpertAugust 17, 2021
    A 7-carat diamond can cost anywhere between $12,000 and $185,000 depending on the quality of the stone. The fewer imperfections, the more expensive the diamond. Some 7-carat diamonds can cost more than $400,000.
  • 1stDibs ExpertSeptember 28, 2021
    A 9-carat diamond’s worth varies depending on the 4Cs of diamond quality — color, cut, clarity and carat. On average, a 9-carat diamond could cost you between $19,000 to $1,000,000. It is also likely that the price range per carat will be even broader. On 1stDibs, you can find a variety of 9-carat diamond jewelry from different periods and styles to choose from.
  • 1stDibs ExpertSeptember 28, 2021
    A 3-carat diamond’s worth varies depending on the 4Cs of diamond quality – color, cut, clarity and carat. On average, a 3-carat diamond could cost you between $7,200 to $51,000. It is also likely that the price range per carat will be even broader. On 1stDibs, you can find a variety of 3-carat diamond jewelry today.
  • 1stDibs ExpertFebruary 22, 2021
    Depending on the quality, age, and designer, a 1-carat diamond can cost between $1,300 and $16,500.
  • 1stDibs ExpertFebruary 27, 2024
    In terms of dimensions, how large a 3-carat diamond is varies. The shape of the diamond will determine its length and width. Weighing 600 milligrams, diamonds that are 3 carats are generally considered to be large stones. On 1stDibs, shop a large collection of diamond jewelry from some of the world's top dealers.
  • 1stDibs ExpertFebruary 22, 2021
    The size of a 12 carat diamond is dependent on diamond cut. A 12 carat round diamond is roughly 15 mm in size.
  • 1stDibs ExpertAugust 24, 2021
    A 2 carat oval diamond is approximately 10.23mm × 6.82mm × 4.16mm in size. These diamonds usually have an approximate face-up area of 57.21 mm². Find a variety of diamonds on 1stDibs.
  • 1stDibs ExpertNovember 2, 2023
    There is no rule for how many carats a diamond wedding ring should be. You're free to choose a ring with a carat weight that appeals to you and fits your budget. The average carat weight for diamond wedding rings is 1 to 1.9 carats. Shop an assortment of diamond wedding rings on 1stDibs.
  • 1stDibs ExpertAugust 17, 2021
    A 7-carat diamond can cost anywhere between $12,000 and $185,000 depending on the quality of the stone. The fewer imperfections, the more expensive the diamond. Some 7-carat diamonds can cost more than $400,000.