Antique Estate Art Deco Platinum Filigree Diamond Openwork Ring Size 4.25 3.3g
Located in Addison, TX
Details: Era: Art Deco Metal: Platinum (Tested, Unmarked) Ring Size: 4.25 Weight: 3.3 Grams Gemstones: Natural Diamonds Diamond Count: 13 Total Diamond Weight: Approx. 0.28 carats M...
Diamond, Platinum
1920s 1.45 Carat Diamond 1.58 Carat Sapphire Platinum Twist Ring
Located in Jesmond, Newcastle Upon Tyne
Condition This stunning antique 1920's sapphire and diamond ring is fine quality set with a natural blue sapphire and a very high color graded old cut diamond.
Diamond, Sapphire, Platinum
Antique Art Deco 1920s 1.50 Carat Diamond Dinner Ring with Emeralds
Located in New York, NY
Finely crafted in platinum with Marquise and Old European cut Diamonds weighing approximately a total of 1.50 carats, and accenting French cut Diamonds. Circa 1920s Size 3 1/2, resiz...
Diamond, Emerald, Platinum
Antique Art Deco Platinum Two Stone Diamond Filigree Shield Ring
Located in Great Neck, NY
Beautiful Antique Art Deco Platinum Two Stone Filigree Shield Ring. This gorgeous ring is crafted in platinum. It has old european cut diamonds set across the top of an Art Deco fili...
Diamond, Platinum
Art Deco Diamond and Blue Sapphire Ring in Platinum
Located in New York, NY
Art Deco Blue Sapphire And Diamond Ring handcrafted In Platinum. The details are as follows : Diamond weight : 1.40 carat approx ( GH color and VS clarity ) Ring size : 6
Diamond, Blue Sapphire, Platinum
Art Deco GIA Certified Fancy Intense Yellow Marquise Diamond Ring
Located in New York, NY
Art Deco GIA Certified Fancy Intense Yellow Marquise Diamond Ring A platinum ring set with a marquise brilliant cut intense yellow cut diamond accented by round cut diamonds. Yel...
Diamond, Platinum
Platinum Art Deco Ring. 1.40ct Old Euro Cut Diamond Square Ring Platinum J VS1
Located in New York, NY
Other Details: Primary Stone: Diamond Center Diamond Weight: 1.40 carats Center Diamond Cut: Old European Cut Center Diamond Color: J Center Diamond Clarity: VS1 Secondary Stones: ...
Diamond, White Gold, Platinum, Gold
Art Deco 1.07 Carat GIA Transitional Cut Diamond & Sapphire Navette Ring
Located in Los Angeles, CA
Super quality Art Deco era 1.07 Carat "Transitional" Cut Diamond & Sapphire Navette Ring composed of platinum. With a 1.07 Carat Transitional Cut diamond (early Round Brilliant Cut),...
Diamond, Sapphire, Platinum
Ring with old mine cut diamond up to 0.75ct 14k gold 2.7 grams
Located in The Hague, ZH
14k yellow gold ring with old mine-cut diamond up to 0.75 ct – G/H - VS/SI - ring size US 5.5 – EU 16(50) Detailed description The top of the ring is 1.3 cm wide and 3.7 mm high. ...
Diamond, 14k Gold
White Diamond and Blue Sapphire Art Deco Ring in 18 White Gold
By Kothari
Located in Los Angeles, CA
Beautiful white diamond round and blue sapphire square ring. Handmade in 18k white gold. Ring size 3.5.
White Diamond, Blue Sapphire, White Gold
Antique Art Deco 1920s 1.50 Carat Old European Cut Diamond Dinner Ring
Located in New York, NY
Finely crafted in platinum with an Old European cut center Diamond weighing approximately 1.50 carats, and smaller Old European cut Diamonds weighing approximately a total of 1.00 ca...
Diamond, Platinum
Antique Art Deco Platinum Old European Cut Diamond Sapphire Shield Ring
Located in Great Neck, NY
Beautiful Antique Art Deco Platinum Old European Cut Diamond Sapphire Shield Ring. This beautiful ring features old european cut diamonds and synthetic sapphires in a long shield rin...
Diamond, Sapphire, Platinum
Antique Art Deco 1920s 0.52 Carat Emerald Cut Diamond Ring with Rubies
Located in New York, NY
Finely crafted in platinum with an Emerald cut Diamond weighing 0.52 carat and accenting Rubies weighing approximately a total of 1.40 carats. Circa 1920s Size 6 3/4, resizable
Diamond, Ruby, Platinum
Antique Art Deco 1920s 2.50 Carat Old Mine Cut Diamond Dinner Ring
Located in New York, NY
Finely crafted in platinum with an Old Mine cut center Diamond weighing approximately 2.50 carat, O-P color, VS clarity. The ring features smaller Old Mine and Old European cut diamo...
Diamond, Sapphire, Platinum
Antique Art Deco 1930s 1.50 Carat Star Ruby Ring with Diamonds
Located in New York, NY
Finely crafted in platinum with a Cabochon Star Ruby weighing approximately 1.50 carat, and Single cut Diamonds weighing approximately a total of 0.60 carat. Circa 1920s Size 6 1/4, ...
Diamond, Star Ruby, Platinum
Antique Art Deco Platinum Old Marquise Baguette & Round Diamond Dinner Ring
Located in Montclair, NJ
--Stone(s):-- (1) Natural Genuine Diamond - Old Marquise Cut - Bezel Set - VS2 Clarity / G Color - 0.50ct (approx.) (18) Natural Genuine Diamonds - Old Marquise, Baguette & Round Cut...
Diamond, Platinum
Antique Art Deco 0.20 ct diamond and ruby ring, 1920s.
Located in Chorzów, PL
An old gold ring in the Art Deco style made of yellow gold (approx. 0.700) with silver elements (0.990). Made in the 1920s in Germany. A centrally placed round diamond in an "old" ...
Diamond, Ruby, Gold, 18k Gold, Silver
Antique Art Deco Platinum Old Euro Diamond and Sapphire Shield Ring
Located in Great Neck, NY
Beautiful Antique Art Deco Platinum Old Euro Diamond and Sapphire Shield Ring. This beautiful shield ring is crafted in platinum. There are old european cut diamonds and French cut s...
Diamond, Sapphire, Platinum
Edwardian Platinum Diamond and Natural Pearl Ring
Located in Chicago, IL
Circa 1920s Platinum Ring in the high Edwardian style, measuring 1 inch in length and 5/8 inch wide at the center. Set with Old cut Diamonds totaling approximately .90 Carat, Central...
Diamond, Natural Pearl, Platinum
French Art Deco Jade Diamond Ring
Located in New York, NY
French Art Deco Jade Diamond Ring Center Diamond approx 1.02 ct Set in Platinum. French Stamp Made In France Circa 1925 Sizable to any size
Diamond, Jade, Platinum
Antique Art Deco Platinum Old European Diamond and Moonstone Shield Ring
Located in Great Neck, NY
Beautiful Antique Art Deco Platinum Old European Diamond and Moonstone Shield Ring. This incredible shield ring has old european cut diamonds all over it in a gorgeous design with a ...
Diamond, Moonstone, Platinum
Antique Art Deco Platinum Old Euro Marquise Diamond and Emerald Shield Ring
Located in Great Neck, NY
Beautiful Antique Art Deco Platinum Old Euro Marquise Diamond and Emerald Shield Ring. This gorgeous antique shield ring is crafted in platinum. The ring has old cut diamonds and an ...
Diamond, Emerald, Platinum
RIng with sapphire and old mine cut diamonds up to 1.45ct 18k gold
Located in The Hague, ZH
18k bicolour gold ring set with 0.75 ct sapphire and 1.45ct old mine cut diamond - G/H - SI - ring size U.S. 8.5 - EU. 18.5 (58) detailed description: the top of the ring is 1.7 cm...
Diamond, Sapphire, 18k Gold
Art Deco Old Mine White & Champagne Diamond You and Me Ring
Located in New York, NY
Art Deco Old Mine White & Champagne Diamond You and Me Ring An Art Deco ring featuring a brown and a white old mine diamond, accented with baguette and round-cut diamonds on bot...
White Diamond, Brown Diamond, Platinum
“Vintage 14k Rose Gold Midnight Blue Sapphire and Diamond Ring, 1920s”
Located in Cairo, EG
14k rose gold color ring centered with natural oval cut mid night blue sapphire colour flanked with 2 rose cut diamonds estimate weight of 0.80 ct
Antique Art Deco 1920s Carved Black Onyx and Coral Ring with Diamonds
Located in New York, NY
Finely crafted in platinum with carved Black Onyx, Red Coral and Diamonds weighing a total of approximately 0.30 carat. Circa 1920s Size 6, resizable
Coral, Diamond, Onyx, Platinum
Art Nouveau Emerald Diamond Ring
Located in Napoli, NA
An Art Nouveau Emerald and diamond ring handcrafted in 18k gold. The ring is set with one beautiful emerald cut 2.90 ct Natural Emerald.T hree rows of sparkling old mine cut diamonds...
Diamond, Emerald, 18k Gold, White Gold
Art Deco 25.0 Carat Moonstone and Diamond Ring
Located in Litchfield, CT
Circa 1920s, Platinum, American. Excellent condition. This ring is a beautiful example of American Art Deco cocktail rings. Today, the look is catwalk to sidewalk American girl gla...
Diamond, Moonstone, Platinum
Art Deco Cornflower Blue Sapphire & Diamond Platinum Ring
Located in Chicago, IL
This exquisite Art Deco era ring presents a captivating centerpiece: a certified, unheated (no heat treatment) cornflower blue sapphire, weighing approximately 0.90 carats. Its rich,...
Diamond, Sapphire, Platinum
Antique 1.41 Carat Emerald Cut Diamond and Emerald Gold Marquise Ring
Located in Jesmond, Newcastle Upon Tyne
This antique 1920s gemstone cocktail ring is supplied with an independent diamond grading report card.
Diamond, Emerald, 14k Gold, White Gold, Gold
Art Deco GIA Certified 3.37ctw Old European Cut Diamond 3-Stone Dinner Ring
Located in Los Angeles, CA
Art Deco era Old European Cut Diamond 3-Stone "Dinner" Ring composed of platinum. Featuring 3 Old European Cut diamonds, one weighing 1.00 carat (GIA certified M color/VS2 clarity), ...
Diamond, Platinum
1 Carat Old European Cut Diamond Art Deco Sapphire Platinum Ring
Located in Chicago, IL
Presenting an exquisite Art Deco ring, masterfully crafted circa the 1920s in solid platinum. This captivating piece features a stunning 1.18 carat Old European cut natural diamond a...
Sapphire, Platinum
Art Deco Ruby and Diamond Ring
Located in New York, NY
Art Deco Ruby and Diamond Ring A platinum ring with fine detailing set with an oval-cut ruby and an antique cut diamond Ring Size: 5.75 Complimentary resizing Signed: Hartdegen M...
Diamond, Ruby, Platinum
Antique Art Deco 14K Yellow Gold and Onyx Diamond Button Ring
Located in Great Neck, NY
Beautiful Antique Art Deco 14K Yellow Gold Platinum Onyx Diamond Button Ring. This beautiful ring is crafted in 14k yellow gold with platinum top. The ring itself is a conversion fro...
Diamond, Onyx, Yellow Gold, Platinum
1920s 15.40 Carat High Zircon and Diamond Ring in 9k Yellow Gold
Located in Jesmond, Newcastle Upon Tyne
A stunning, fine and impressive antique 15.40 carat high zircon, 0.56 carat diamond, 9 karat yellow gold and silver set ring; part of our collection of gemstone engagement rings. Th...
Diamond, Zircon, Yellow Gold, Silver
Antique Art Deco 18K Rose Gold Pearl and Rose Cut Diamond Ring
Located in Great Neck, NY
Beautiful Antique Art Deco 18K Rose Gold Pearl and Rose Cut Diamond Ring. This beautiful ring is crafted in 18k rose gold. The center holds 3 beautiful pearls and has rose cut diamon...
Diamond, Pearl, Rose Gold
1920s Platinum Art Deco 1 Carat Diamond Antique Ring Handmade American Size 5.75
Located in Santa Monica, CA
1920s Platinum Art Deco 1 Carat total Diamond weight Toi et Moi Design Antique Ring Size 5.75 9.2 gram Earth mined Diamonds; 28 pieces estimated of 0.02 Carat each single cut di...
Diamond, Platinum
Antique Art Deco 18 Karat White Gold Diamond and Sapphire Shield Ring
Located in Great Neck, NY
Gorgeous Antique Art Deco 18K White Gold Diamond and Sapphire Shield Ring. This beautiful art deco shield ring features amazing old european cut diamonds and sapphires on a filigree ...
Diamond, Sapphire, White Gold
Art Deco 18K White and Yellow Gold, Blue Enamel, and Diamond Ring
Located in Venice, CA
This is a gorgeous 18k white and yellow gold ring, made in Italy in the Art Deco period. The shape of this ring is quite unique, with a yellow gold shell-like swirl that extends and ...
Diamond, 18k Gold, White Gold, Yellow Gold, Enamel
Vintage Inspired Emerald Diamond 18K Yellow Gold Ring Cluster Ring
Located in Beverly Hills, CA
Brand: Trampet&Horn Center Stone: Emerald Cut: Oval Weight: Approximately 1.25 Carats Color: Green Accent Stone: 12 Diamonds Cut: Round Brilliant Weight: Approximately 0.58 Carats Co...
Diamond, Emerald, Gold, 18k Gold, Yellow Gold
An Art Deco Platinum and DIamond Ring, 0.8 total carats
Located in Lambertville, NJ
A sweet Art Deco diamond ring crafted in platinum. It features 0.80 carat total weight of natural mine cut, SI1-I1 clarity, I-J color diamonds. The detailing on this piece is truly a...
Diamond, Platinum
Antique Art Deco 1920s 6.00 Carat Star Ruby and Diamond Halo Ring
Located in New York, NY
Finely crafted in platinum with a Cabochon Star Ruby weighing approximately 6.00 carats, accented by a halo of Old European cut Diamonds weighing a total of approximately 2.00 carats...
Diamond, Star Ruby, Platinum
Vintage Palladium 1.13 CTW Diamond and Sapphire Ring
Located in Ocala, FL
A distinctive vintage palladium ring showcasing an elegant asymmetrical bypass design accented with diamonds and sapphires. The composition features two old European-cut diamonds tot...
Diamond, Sapphire, Palladium
Antique Edwardian Pink Flame Conch Pearl Platinum PT900 Bow Diamond Ring 6.25
Located in Jersey City, NJ
This exquisite vintage ring, believed to be from the Edwardian era (circa 1910-1930), showcases a unique bow motif crafted in Platinum PT900 and adorned with 38 single-cut diamonds, ...
Diamond, Pearl, Platinum
Art Deco Platinum Diamond Ring with 3.02 Carat Old Mine Cut Center and Baguettes
Located in Great Neck Plaza, NY
An exceptional Art Deco platinum ring, centering a dazzling old mine cut diamond weighing 3.02 carats, mounted in a finely detailed hand-engraved setting. The center stone is flanked...
Diamond, Platinum
Antique Art Deco 1920s 1.60 Carat Old Mine Cut Diamond Octagonal Ring with Onyx
Located in New York, NY
Finely crafted in platinum with an Old Mine cut Diamond weighing approximately 1.60 carat, J color, SI1 clarity. The ring features an Onyx and a halo of Single cut Diamonds. Circa 19...
Diamond, Onyx, Platinum
Antique 1.10 Carat Diamond Elongated Ring. Old Euro and Sapphire Platinum K VS2
Located in New York, NY
Other Details: Primary Stone: Diamond Center Diamond Weight: 1.10 Carats Center Diamond Cut: Old European Cut Center Diamond Color: K Color Center Diamond Clarity: VS2 Clarity Seco...
Diamond, Sapphire, Platinum
Vintage ring with sapphire and old mine cut diamond up to 0.60ct 18k gold 7.0 gr
Located in The Hague, ZH
18k yellow gold ring set with sapphire totaling 1.00ct and a central old mine cut diamond totaling 0.60ct - J/K - VS/SI - ring size U.S. 7.25 - EU. 17.5(55) detailed description: t...
Diamond, Sapphire, 18k Gold
Art Deco 1920s Platinum & 18K Yellow Gold Emerald & Diamond Panel Ring
Located in Staines-Upon-Thames, GB
An Art Deco emerald, diamond, platinum and yellow gold ring, comprising one square cut emerald, and old round cut diamonds, set in platinum, to an 18 karat yellow gold band. This ...
Diamond, Emerald, 18k Gold, Yellow Gold, Platinum
Antique Art Deco 14k Gold Old European Diamond Round Open Milgrain Platter Ring
Located in Montclair, NJ
Here we have a beautiful, antique, diamond platter ring crafted in solid 14k white gold during the art deco period and features a round open design with milgrain etching work through...
Diamond, 14k Gold, White Gold
Art Deco Old European Cut Yellow Diamond Ring
Located in West Palm Beach, FL
Elegantly crafted circa 1920, this enchanting bombe ring is composed of platinum and 18k white gold. At its center rests a captivating Old European cut fancy yellow diamond of SI cla...
White Diamond, Yellow Diamond, 18k Gold, Platinum
Antique Art Deco 14k Yellow Gold Platinum Old Mine Diamond Burma Ruby Ring
Located in Great Neck, NY
Beautiful Antique Art Deco 14K Yellow Gold Platinum Old Mine Diamond Burma Ruby Ring. This gorgeous saddle ring is crafted in 14k yellow gold and platinum. The center holds a natural...
Diamond, Ruby, Yellow Gold, Platinum
Art Deco 2.50 Carat Emerald and Diamond Ring
Located in Carmel-by-the-Sea, CA
Intricate art deco architecture encircles a 2.50 carat emerald. Boasting striking color and excellent transparency, the stone sits protected in its platinum bezel and complimented by...
Diamond, Emerald, Platinum
Art Deco Baguette and OEC Diamond Platinum Vintage Navette Ring
Located in Montreal, QC
Simply Beautiful! Finely detailed Art Deco Diamond Platinum Navette Vintage Cocktail Ring. Securely Hand set with Baguette & Old European Cut Diamonds. Hand crafted Platinum moun...
Diamond, Platinum
Vintage Art Deco 18K Gold Pearl & Old Mine Diamond Ring with Rose-Cut Halo
Located in MONTMORENCY, FR
This elegant Art Deco ring, crafted in rich 18K yellow gold (750‰), presents a poised vertical “figure-8” motif set with a lustrous natural pearl at its center. At the top and bottom...
Diamond, Pearl, 18k Gold
Art Deco inspired 1.97 carat emerald diamond platinum ring
Located in Beverly Hills, CA
A striking modern ring inspired by the bold geometry of the Art Deco period, this elegant design centers on a vivid 1.97 carat emerald cut emerald. The clean step-cut facets highligh...
Diamond, Emerald, Platinum
1920s Sugarloaf Cabochon Cut Emerald and Diamond 18 Karat White Gold Ring
Located in Bay Harbor Islands, FL
This sugarloaf cabochon bezel set emerald sits in the center, surrounded by one row of 12 Old European cut diamonds weighing approximately 1.70 carats. It is further surrounded by a ...
Diamond, Emerald, 18k Gold, White Gold
Antique Art Deco Yellow Gold Oval Black Onyx & Old Diamond Large Ring
Located in Montclair, NJ
–Stone(s)– (1) Natural Genuine Diamond - Old European Cut - Pave Set - White Color - 0.04ct (approx.) (1) Natural Genuine Onyx - Oval Cut - Prong Set - Black Color - 25.2x18.1mm (app...
Diamond, Onyx, Gold, 10k Gold, Yellow Gold
Art Deco natural pearl and diamond ring, circa 1925.
Located in London, GB
Art Deco natural pearl and diamond ring. Centrally set with a cushion shape old mine diamonds in an open back claw setting with a an approximate weight of 1.45 carats decorated to to...
Diamond, Natural Pearl, Platinum
Contemporary 5.00 carat ruby diamond 18k white gold ring
Located in Beverly Hills, CA
Vivid and full of presence, this Contemporary ring showcases a cushion cut ruby weighing approximately 5.00 carats at its heart. The ruby's deep, saturated red commands the eye insta...
Diamond, Ruby, Gold, 18k Gold, White Gold
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 rings, vintage engagement rings or Art Deco engagement rings.
Shop antique and vintage diamond rings, diamond necklaces and other extraordinary diamond jewelry on 1stDibs.
A flashy symbol of wealth during the early 20th century, antique and vintage cocktail rings have gained broader appeal in the decades since for the hefty dose of glamour they bring to any ensemble.
Cocktail rings earned their name for their frequent appearances during glitzy cocktail parties at the height of the Prohibition era. Back then, these accessories were seen not only as statement pieces but as statements in and of themselves. They openly represented a sense of freedom and independence as well as a demonstration of opulence. After all, the 1920s heralded the Harlem Renaissance and Art Deco design, and a slew of social and cultural shifts meant that women in particular were breaking from pre–World War I conventions and embracing newfound freedoms to express themselves as individuals.
Women expressly wore cocktail rings on the fingers of their right hand versus the left, which was “reserved” for an engagement ring or wedding band, accessories definitely paid for by a suitor. And for cocktail rings, the bigger the colored gem at the center — which is usually mounted in a high setting — and the more elaborate the design, the stronger the likelihood of being noticed.
Cocktail rings remained a popular piece of jewelry for women until the 1930s, when the Great Depression and the onset of war marked a change in behaviors nationwide. While the 1960s and ’70s saw a return in visibility for the accessory, it wasn’t until the 1980s that cocktail rings once again assumed their position as a beacon of luxury and glitz.
During the 20th century, the range of dazzling cocktail rings seems to have been limitless, from glimmering gold rings set with carved jade diamonds designed by David Webb to Pomellato’s pink quartz confections to striking Gucci butterfly rings with accent diamonds set in a pavé fashion.
So, how do you wear a cocktail ring? Cocktail rings “can be worn for almost anything — dinners, date nights, parties, special events, on the red carpet,” explains David Joseph of New York-based jewelry brand Bochic.
Can you wear cocktail rings with other rings? “In my opinion, cocktail rings should stand on their own since they showcase a large gem in the center,” says Joseph.
These glamorous jewels can be worn inside or outside crowded taverns, in either daytime or nighttime with casual or dressy attire. On 1stDibs, find a wide variety of antique and vintage cocktail rings, including those offered by Chanel, whose elegant cocktail rings often feature pearls and, of course, diamonds, and sometimes were styled after showy flowers like the camellia, and Van Cleef & Arpels, whose detailed and intricate designs are viewed as miniature pieces of wearable art.
Learn about these antique jewelry styles, then choose a design that speaks to you.
Ready to rock? Some of our favorite jewelry designers and dealers share indispensable advice for choosing that most important ring.
Will your beloved be enchanted by an Edwardian ring or a trendy Art Deco piece? We clue you into period styles and tips for finding the perfect ring.