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Art Nouveau Genuine Opal Cabochon and Rhinestone Drop Screwback Earrings, 1940s
Located in Tucson, AZ
punctuated by a perfect 12 mm opal cabochon. Petite yet statement-making and thoroughly mesmerizing
Category
Vintage 1940s Unknown Art Nouveau Drop Earrings
Materials
Opal, Base Metal
W 0.63 in D 0.38 in L 1.13 in
Dalben Rough Amber and Australian Opal Necklace
By Laura Dalben
Located in Como, IT
mm , opals 11-7 mm .
Category
21st Century and Contemporary Italian Contemporary Beaded Necklaces
Materials
Amber, Opal, 18k Gold, Rose Gold
Antique French Opal and Diamond Ring
Located in London, GB
: 1.8 grams
Size: J (49)
Face Dimensions: 13.5mm x 12mm
Opal: 1 (8mm x 5mm x 2mm)
Diamonds: Approx. 0.08
Category
Antique Early 1900s Art Nouveau Fashion Rings
Materials
Diamond, Opal, Gold, Yellow Gold
White Opal and Diamond Abstract Ring
Located in London, GB
Dimensions: 15mm x 12mm
Opal: Approx. 0.78ct
Diamond: 2mm
Marked: '750' i.e. 18ct
Box: The Vintage Jeweller
Category
Late 20th Century Fashion Rings
Materials
Diamond, Opal, Gold, White Gold, Yellow Gold
Boulder Opal and Diamond Abstract Ring
Located in London, GB
.
Condition: Used (Very Good)
Weight: 6.0 grams
Size: M (53)
Resizable: Yes
Face Dimensions: 14mm x 12mm
Opal
Category
20th Century Fashion Rings
Materials
Diamond, Opal, 18k Gold, Yellow Gold
Black Opal Yellow Gold Stud Earrings Natural Blue Opal Australian
By Alexey Gabilo
Located in Berlin, DE
- 0.16 x 0.2 x 0.47 in / 4 х 5 х 12 mm
Opal weight - 3.25 carats
earrings weight - 4.4 grams
We ship
Category
2010s German Artisan Stud Earrings
Materials
Opal, Black Opal, Yellow Gold
H 0.48 in W 0.2 in D 0.16 in L 0.48 in
Ethiopian Opal Pair total 5 ct 12 mm x 10 mm AAA+ Great Fire Create your Earring
Located in Viena, Viena
this pair of very fine Ethiopian opal cabochons can be a amazing jewelry, 2 opal with 12 x 10 mm
Category
2010s Modern Loose Gemstones
Materials
Opal
W 0.48 in D 0.16 in L 0.4 in
Australian Loose Solid Opal of 7.50ct (27mm x 12mm). Lightning Ridge.
Located in MELBOURNE, AU
This Australian Loose Solid Opal is
of impressive 7.50ct (27mm x 12mm)
from Lightning Ridge
Category
Vintage 1980s Australian Loose Gemstones
Materials
Opal
Magnificent Australian Loose Black Boulder Opal of 5.50ct. 19mm x 12mm x 4mm.
Located in MELBOURNE, AU
This Australian Loose Boulder Opal is
of impressive 5.50ct (19mm x 12mm x 4mm)
from Winton
Category
Vintage 1980s Australian Loose Gemstones
Materials
Opal
W 0.48 in D 0.16 in L 0.75 in
14 Karat Black Opal and Diamond Pendant
Located in Washington Depot, CT
opal (12 mm x 9 mm) and two baguette diamonds set in classic 18K yellow gold.
*Chain not included
Category
20th Century Pendant Necklaces
Materials
Diamond, Opal, Black Opal, Yellow Gold
Antique Victorian Opal Diamond Gold Bangle Bracelet
Located in Miami, FL
, measuring 12 mm approximately, 6 carats in total.
(40) Natural genuine old mine diamonds enrich this
Category
Antique Early 1900s Late Victorian Bangles
Materials
Diamond, Opal, Gold
Navy Blue Australian Opal ring silver Statement gift for friend anniversary
Located in Berlin, DE
, diameter 19 mm, N 20, 60 circumference
ring weight - 15 grams
stone measurements - 0.47 х 0.83 in / 12 х 21
Category
2010s German Artisan Cocktail Rings
Materials
Opal, Black Opal, Silver
Black Opal Yellow Gold Pendant Navy Blue Unisex Jewelry
Located in Berlin, DE
measurements - 0.2 х 0.47 х 0.71 in / 5 х 12 х 18 mm
opal weight - 8.40 carats
pendant length - 1.02 in / 26 mm
Category
2010s Artisan Pendant Necklaces
Materials
Opal, Black Opal, Gold, 18k Gold, Yellow Gold
Vintage 4 Opal Drop Pendant Necklace 14k Yellow Gold
Located in Honolulu, HI
3.47 mm, side opals: 8mm x 5mm x 3 mm, bottom opal: 12 mm x 6 mm x 3 mm
Opal Carat Weight: ~4.5
Category
21st Century and Contemporary Unknown Modern Pendant Necklaces
Materials
Opal, Yellow Gold, 14k Gold
Steven Battelle 11.3 Carats Boulder Opal 18K Gold Ring
By Steven Battelle
Located in Soquel, CA
A bright, electric blue, variegated 12 x 27 mm oval boulder opal is set vertically in an
Category
21st Century and Contemporary Balinese Contemporary Cocktail Rings
Materials
Opal, 18k Gold
BLUE OPAL NECKLACE with DIAMOND & BLUE SAPPHIRES, 14K GOLD
By Jen Proudman Jewelry
Located in New York, NY
.
The first pendant is a carved blue opal shell (12mm diameter) with a center 2mm round diamond bezeled
Category
21st Century and Contemporary American Pendant Necklaces
Materials
Diamond, Opal, Blue Sapphire, 14k Gold
14 Karat Yellow Gold Opal Triplet and Diamond Ring #13915
Located in Washington Depot, CT
features one oval cabochon mosaic opal triplet (12 mm x 11 mm) and ten round brilliant cut diamonds set in
Category
20th Century Cocktail Rings
Materials
Diamond, Opal, Yellow Gold
Important Arts and Crafts Black Opal Galleon Necklace
Located in Riverdale, NY
. The central motif is a gold galleon set with a large amazing Black opal (12mm x 10mm), likely of
Category
Vintage 1910s American Arts and Crafts Drop Necklaces
Materials
Opal, Citrine, 14k Gold, Sterling Silver
3.24 Carat Opal Diamond 18 Karat Rose Gold Ring
By Roshe Jewels
Located in Los Angeles, CA
The Oval Cut Opal in this ring weighs 2.67 Carats and the measurements of the Opal are 8 mm x 12 mm
Category
21st Century and Contemporary American Contemporary Cluster Rings
Materials
Pink Sapphire, Opal, Diamond, 18k Gold, Rose Gold
Edwardian Giant Opal Ring Vintage Antique 14K Yellow Gold Original 1900'
Located in Dearborn, MI
Yellow Gold
Featuring a GIANT Fiery 20 x 12mm Oval Cabochon Opal Center
This Ring Was Hand Made Over
Category
Vintage 1910s Edwardian Cocktail Rings
Materials
Opal, 14k Gold, Yellow Gold
2.91 Carat Opal Diamond 18 Karat Yellow Gold Ring
By Roshe Jewels
Located in Los Angeles, CA
2.30 Carats and the measurements of the Opal are 8 mm x 12 mm. The Opal is surrounded by 4 Pink
Category
21st Century and Contemporary American Modern Cocktail Rings
Materials
Pink Sapphire, Opal, Diamond, Yellow Gold, 18k Gold
Vintage Opal and Diamond Cocktail Ring in Yellow Gold, Italian
Located in Coral Gables, FL
Large 18 Karat Yellow Gold Vintage Cocktail Ring Featuring A 15mm x 12mm Oval Opal Weighing
Category
Mid-20th Century Italian Cocktail Rings
Materials
Diamond, Opal, 18k Gold, Yellow Gold
Griffin Dragon Black Opal Pendant Necklace Antique Belle Epoque 14 Karat Gold
Located in New York, NY
15mm long without the loops. It is 12mm wide.
The opal is 9mm by 6mm.
The pendant weighs 1 gram.
The
Category
Antique 19th Century Unknown Belle Époque Pendant Necklaces
Materials
Opal, Black Opal, Gold, 14k Gold, Yellow Gold
Gorgeous Vintage Opal and Diamond Halo Platinum Ring Engagement Ring
Located in San Francisco, CA
Stunning Opal center! In the center, the ring holds One Opal, 16mm x 12mm, approximately 6.00 carat, of
Category
Early 20th Century American Art Deco Engagement Rings
Materials
Diamond, Opal, Platinum
Art Deco Opal Black Onyx Ring 14 Karat Gold Antique
Located in New York, NY
ring or a dramatic everyday treasure!
Opal
The oval opal cabochon is 12mm by 8mm.
Colors: Blue, Green
Category
Early 20th Century Unknown Art Deco Cocktail Rings
Materials
Opal, Onyx, Gold, 14k Gold, Rose Gold
9K Rose Gold 6.00ct Australian Opal Retro 60's Set: Earrings & Pendant + Chain
Located in MELBOURNE, AU
(doubles),
with bigger one measuring 12mm x 10mm
Opals are exhibiting magnificent spectrum of colours
Category
Vintage 1960s Australian Retro Clip-on Earrings
Materials
Opal, Rose Gold
H 1.3 in W 0.4 in L 0.6 in
6 Carat Mexican Fire Opal Diamond Halo Ring 14 Karat Gold Antique Cocktail Ring
Located in New York, NY
opal is 14mm by 12mm by 6mm. Surrounding the opal is a halo of 20 sparkling round white diamonds
Category
20th Century Unknown Contemporary Cocktail Rings
Materials
Diamond, Fire Opal, Opal, White Gold, 14k Gold, Gold
Ethiopian Opal & Multi Stone Studded Enamel Ring in 14 Karat Gold
Located in JAIPUR, IN
:
Ethiopian Opal : 12 x10 mm
Ruby : 4x2 mm
Tsavorite: 1.0 x1.0 mm; 1.5 x 1.5 mm
Gemstone Carat Weight
Category
2010s Indian Contemporary Cocktail Rings
Materials
Diamond, Opal, Ruby, Tsavorite, 14k Gold, Yellow Gold, Enamel
Eternity Heart Australian Crystal Opal Circle Necklace Pendant 14K Yellow Gold
Located in Suwanee, GA
.
----------------------------------------------------------------------------------------------------
ABOUT THIS PRODUCT
Solid 14K Yellow Gold
Australian Solid Opal, 0.91 ct
Penda...
Category
2010s American Arts and Crafts Pendant Necklaces
Materials
Crystal, Opal, 14k Gold, Yellow Gold
Vintage Natural Opal Diamond Ring 14k White Gold Cocktail Oval Estate Jewelry
Located in Torrance, CA
white gold.
Solid natural opal measures 12mm x 10mm (estimated at 5 carats) accented with 14 estimated
Category
Mid-20th Century Unknown Modern Cocktail Rings
Materials
Opal, White Diamond, Diamond, White Gold, 14k Gold, Gold
Opal Diamond Ring East West Sz 7 Estate Fine Jewelry 14k Rose Gold Band
Located in Torrance, CA
Stylish opal & diamond ring crafted in 14 karat rose gold.
Opal measures 12mm x 3mm. Diamonds
Category
Mid-20th Century Unknown Modern Band Rings
Materials
Opal, White Diamond, Diamond, Rose Gold, 14k Gold, Gold
Opal and Diamond Halo 14k pendant. Large Natural Pendant Surrounded by Baguette
Located in Port Charlotte, FL
total
12mm by 20mm Pearl Cabochon Opal
est at 1.40 ct VS G Color diamonds.
20in cable 14k Chain Necklace
Category
Early 2000s Pendant Necklaces
Opal Engagement Ring, Fire Opal Ring, Opal Wedding Ring, Dainty Opal Ring
Located in New York, NY
: Natural
✔ Stone: Natural Ethiopian Opal
✔ Number of Stones: 1
✔ Number of Diamonds: 12
✔ Opal Size: 5 mm x
Category
2010s American Artisan Fashion Rings
Materials
Opal, Gold, 14k Gold, 18k Gold, White Gold, Yellow Gold
Large Vintage 14 Karat Gold Scorpion Natural Opal Brooch Pin with Opal Eyes
Located in Overland Park, KS
Large 1 3/4" Vintage 14k Yellow Gold Scorpion with a Natural Opal Brooch Pin with Opal Eyes. 12mm
Category
Late 20th Century Unknown Contemporary More Jewelry
Materials
Opal, Yellow Gold, 14k Gold
Art Deco Natural Black Opal Diamond Ring 8 Carat Opal Platinum, circa 1920
Located in Lancaster, Lancashire
offer this service for free, it takes approximately one week.
OPAL MEASURES: Width 12mm x Height 15mm
Category
Vintage 1920s British Art Deco Fashion Rings
Materials
Diamond, Opal, Platinum
Peruvian Opal White Cultured Pearl Long Gemstone Necklace
By de la Vega designs
Located in Coral Gables, FL
may also be worn as a lariat. The Peruvian opal is 12mm roundels, the pearls are white and it is
Category
2010s American Contemporary Beaded Necklaces
Materials
Cultured Pearl, Opal, Sterling Silver
Antique Fontana boxed 18K gold opal diamond pin brooch
By Fontana
Located in Versailles, FR
opal.
Traces of uses.
French eagle’s head hallmark for 18K gold
The opal measures 12mm in length and
Category
Antique 19th Century French Victorian Brooches
Materials
Diamond, Opal, 18k Gold
NIXIN Jewelry Adriatic Mist Australian Opal Ring with Emerald & Tourmaline
Located in Los Angeles, CA
yours.
DIMENSIONS:
• Opal Frame: approximately 12mm tall x 10mm wide x 4.3mm deep (8.4 including the
Category
2010s American Contemporary Cocktail Rings
Materials
Emerald, Opal, Spinel, Tourmaline, Black Opal, Gold, 14k Gold, Yellow Gold
Pink Explosion Gold Ring with Opal, Diamonds and Gemstones
By Katerina Marmagioli
Located in Nea Aghialos Magnesias, GR
100% Recycled 14 K Yellow gold
One round cabochon pink opal (12mm/0.472 inches)
Six green
Category
2010s European Contemporary Cocktail Rings
Materials
Diamond, Opal, Tsavorite, Gold
Square Fire Opal and Diamond Cluster Ring 18 Karat Yellow & White Gold
Located in East Grinstead, GB
Square Fire Opal and Diamond Cluster Ring 18 Karat Yellow & White Gold
Classic fire opal and
Category
21st Century and Contemporary British Art Deco Cluster Rings
Materials
Fire Opal, Opal, White Diamond, Diamond, Yellow Gold, White Gold, 18k Go...
Antique Victorian 35 Carat Opal Cross Pendant Diamond 18 Carat Gold, circa 1900
Located in Lancaster , GB
: Width 37mm x Height 65mm x Depth 7mm
OPALS MEASURE: largest 12mm x 11mm / Smallest 11mm x 8mm
METAL
Category
Antique Early 1900s British Victorian Pendant Necklaces
Materials
Diamond, Opal, 18k Gold, Yellow Gold
H 2.56 in W 1.46 in D 0.28 in
Doves 18 Karat Gold Dangle Earrings with Cabochon Round Pink Opal and Diamonds
By Doves by Doron Paloma
Located in Great Neck, NY
Dahlia Collection Dangle Earrings, with round cabochon-cut Pink Opal, a halo of diamonds, and gold
Category
21st Century and Contemporary American Contemporary Dangle Earrings
Materials
Diamond, Onyx, Opal, White Diamond, 18k Gold, Yellow Gold
8.3 Carat Australian Coober Pedy Opal, Diamonds, Rubies Etruscan Cuff Bracelet
Located in Pacific Palisades, CA
Coober Pedy Opal: 20mm x 12mm;
36 hand set brilliant white diamonds 1.40 total carat weight, VS1, Color
Category
2010s American Cuff Bracelets
Materials
18k Gold, Yellow Gold
14 Karat Vintage Oval Opal and Diamond Halo Cocktail Ring
Located in Coral Gables, FL
14 Karat Yellow Gold Wirework Cocktail Ring Featuring a 16mm x 12mm Opal Surrounded By 24 Single
Category
Mid-20th Century Cocktail Rings
Materials
Diamond, Opal, 14k Gold, Yellow Gold
Ethiopian Opal 14K Yellow Gold Ring Lemon Green Natural Gemstone Engagement Ring
Located in Berlin, DE
stone,
opal origin - Ethiopia
opal measurements - 0.28 х 0.39 х 0.47 in / 7 х 10 х 12 mm
opal weight
Category
2010s Russian Art Nouveau Engagement Rings
Materials
Opal, 14k Gold, Yellow Gold
Art Deco Opal Ring
Located in New York, NY
This unique platinum ring features a stunning 19mm x 12mm black opal. The opal is bezel set in a
Category
Early 20th Century American Art Deco More Rings
Materials
Diamond, Opal, Platinum
14 Karat Yellow Gold Opal Ring
Located in Washington Depot, CT
Vintage 14 Karat Yellow Gold Opal Ring Size 7.25
This lovely ring features one round opal (12 mm
Category
20th Century Fashion Rings
Materials
Opal, Gold
Mid 20th Century Australian Opal Ring
Located in ADELAIDE, SA
cut, solid white opal (15.7mm x 12mm), Class 1, transparent light rolling pattern, medium green/orange
Category
Mid-20th Century Modern Cocktail Rings
Materials
Opal, 18k Gold
Vintage Opal and Diamond Cluster Ring
Located in London, GB
Good)
Weight: 4.1 grams
Size: N 1/2 (54)
Face Dimensions: 12mm x 11mm
Opal: Approx. 0.60 carats
Total
Category
20th Century Victorian Cluster Rings
Materials
Diamond, Opal, Gold, Yellow Gold
14 Karat Yellow Gold and Opal Brooch / Pendant
Located in Washington Depot, CT
mm x 8 mm and 12 round opals, 4 mm each, set in beautifully detailed 14K yellow gold. Can be worn as
Category
20th Century Brooches
Materials
Opal, Gold
White Opal and Diamond Abstract Ring
Located in London, GB
Dimensions: 12mm x 8mm
Opal: Approx. 0.70 carats
Diamonds: 6 (1mm)
Marked: '750' i.e. 18ct
Box: The Vintage
Category
21st Century and Contemporary Fashion Rings
Materials
Diamond, Opal, Gold, Yellow Gold
7 Carat Glitering Mexican Fire Opal Sterling Silver Ring
By Aria Jewelry Design
Located in Raleigh, NC
Brilliant flashing goldy yellow 16.2 mm x 12 mm - 7 carat - Mexican Fire Opal set in this sterling
Category
21st Century and Contemporary American Cocktail Rings
Materials
Opal, Sterling Silver
Vintage Solid 24 Karat Yellow Gold and Opal Ring 5.9g
Located in Manchester, NH
a vibrant opal. This opal measures approximately 12mm X 9.85mm. This opal is blue and green with
Category
21st Century and Contemporary Unknown More Rings
Materials
Opal, Yellow Gold
Jill Garber Antique Figural Goddess with Australian Opals Elizabethan Necklace
By Jill Garber
Located in Saginaw, MI
ornament, the festoon drop with engraved pattern details frames an 10 x 12 mm Australian Opal that
Category
2010s American Artist Drop Necklaces
Materials
Opal, Sterling Silver
70s Freeform Mexican Fire Opal Necklace Pendant 14k Yellow Gold Orange Jewelry
Located in Torrance, CA
(circa 1970s).
Freeform natural opal measures 12mm x 10mm. The opal is in very good condition and free
Category
Late 20th Century Unknown Modern Pendant Necklaces
Materials
Opal, Fire Opal, Gold, 14k Gold, Yellow Gold
H 1 in W 0.5 in L 19.5 in
Antique Natural Opal Diamond Ring Art Deco Platinum Vintage Cocktail Ring
Located in Torrance, CA
.
Centrally mounted natural opal measures 12mm x 8mm (estimated at 4 carats), accented with 78 graduated
Category
Early 20th Century Unknown Art Deco Cocktail Rings
Materials
Diamond, Opal, Platinum
Antique Victorian Jelly Opal Ring 10 Karat Yellow Gold Vintage Fine Jewelry
Located in Torrance, CA
gold.
Natural cabochon cut opal measures 12mm x 10mm (estimated at 4 carats). The opal is in
Category
Antique Late 19th Century Unknown Victorian Cocktail Rings
Materials
Opal, 10k Gold, Yellow Gold
Vintage Spider Pendant Charm Ethiopian Fire Opal 10 Karat Gold Estate Jewelry
Located in Torrance, CA
(circa 1960s to 1970s).
Ethiopian opal measures 12mm x 8mm (estimated at 3 carats). The opal is in
Category
Mid-20th Century Unknown Modern Pendant Necklaces
Materials
Opal, 10k Gold, Yellow Gold
Vintage 1970s Natural Opal Ring 14 Karat Gold Abstract Design Pinky Jewelry
Located in Torrance, CA
yellow gold.
Cabochon oval opal measures 12mm x 10mm (estimated at 5.50 carats). The opals are in
Category
Late 20th Century Unknown Modern Cocktail Rings
Materials
Opal, 14k Gold, Yellow Gold
Vintage Oval Opal with Single Diamond 14 Karat Two-Tone Gold Ring
Located in Addison, TX
: 20.9 mm at head tapering to 3.3 mm at bottom of the shank
Finger to Top of Stone Measurement: 12 mm
Category
Early 2000s Contemporary Fashion Rings
Materials
Diamond, Opal, Gold, 14k Gold, White Gold
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12mm Opal For Sale on 1stDibs
Surely you’ll find the exact 12mm opal you’re seeking on 1stDibs — we’ve got a vast assortment for sale. Every item for sale was constructed with extraordinary care, often using gold, yellow gold and 14k gold. Find an antique version now, or shop for 441 vintage or 334 modern creation for a more contemporary example of these cherished accessories. If you’re looking for a 12mm opal from a specific time period, our collection is diverse and broad-ranging, and you’ll find at least one that dates back to the 18th Century while another version may have been produced as recently as the 21st Century. Finding an appealing 12mm opal — no matter the origin — is easy, but LB Exclusive, Tutti Frutti Jewellery and Laura Dalben each produced a popular version that is worth a look. A 12mm opal can make for a versatile accessory, but a selection from our variety of 472 opal versions can add an especially stylish touch. An oval cut version of this piece has appeal, but there are also cabochon and round cut versions for sale. There aren’t many items for men if you’re seeking a 12mm opal, as most of the options available are for women and unisex.
How Much is a 12mm Opal?
On average, a 12mm opal at 1stDibs sells for $1,650, while they’re typically $100 on the low end and $42,000 for the highest priced versions of this item.