Size Wedding Rings
34
2,190
42
to
608
1,598
218
3
3.25
3.5
3.75
4
4.25
4.5
4.75
5
5.25
5.5
5.75
6
6.25
6.5
6.75
7
7.25
7.5
7.75
3
11
130
2,088
2
5
12
5
6
3
3
3
4
14
248
190
114
73
64
1,299
909
24
1,954
1,005
917
814
697
1,820
252
196
163
161
766
179
176
132
115
to
697
585
265
37
25
23
8
7
3
3
3
3
2
1
1
Ring Size: 7
TJD 1.0 Carat Natural Diamond 14 Karat White Gold Wedding Band Ring
By TJD
Located in New York, NY
This beautiful engagement band ring features shimmering baguette diamonds and brilliant cut round diamonds in prong and channel setting. Crafted in 14 karat white gold. The ring is s...
Category
2010s Indian Contemporary Wedding Rings
Materials
Diamond, White Gold, 14k Gold
1.24 Carat Opal Oval Cab and Diamond 10K Rose Gold Classic Ring
Located in New York, NY
A gorgeous oval-cut Australian Opal gemstone centers this remarkable Gin & Grace ring and accented with round-cut diamonds on its sides. Crafted of beautiful 10-karat rose gold, this...
Category
20th Century Chinese Art Deco Wedding Rings
Materials
Diamond, Opal, 10k Gold, Rose Gold
Diamond Engagement Ring Set 14K White Gold Bands by OTC
Located in East Brunswick, NJ
Diamond Engagement Ring Set 14K White Gold Bands by OTC
This beautiful bridal set is finely crafted in solid 14K White gold. Both rings are hallmarked "OTC" inside the shanks. The e...
Category
20th Century Bridal Rings
Materials
Diamond, 14k Gold, White Gold
3 round moissanite 14k gold engagement ring.
Located in Istanbul, TR
3 round moissanite 14k gold engagement ring. Vintage engagement moissanite ring. Moissanite gold ring. Round moissanite ring.
Metal: 14k gold
Weight: 3 gr depends from size
Gemsto...
Category
2010s Turkish Modern Wedding Rings
Materials
Diamond, 14k Gold
TJD 3.00 Carat Round Diamond 14 Karat White Gold Full Eternity Wedding Ring
By TJD
Located in New York, NY
Honor the women you love with this eternity wedding band is expertly crafted in 14 Karat White Gold and features 200 round diamond set in microprong setting. This eternity band has h...
Category
21st Century and Contemporary Wedding Rings
Materials
Diamond, White Gold
0.92 Carats Ruby and Diamond Eternity Ring in 14k White Gold
Located in New York, NY
We present to you this beautiful 0.92 Carats Ruby and Diamond Eternity Ring made in 14K White Gold. This ring consists of 2.3mm rubies and diamonds rounds with 9 ruby pieces and 8 di...
Category
21st Century and Contemporary American Modern Wedding Rings
Materials
Diamond, Ruby, White Gold
Ladies 14K Rose Gold 2.09CT Oval Half Eternity Seven Across Diamond Wedding Band
Located in Houston, TX
Gender: Ladies
Metal Type: 14K Rose Gold
Size: 7
Shank Maximum Width: 2.70 mm
Weight: 3.20 Grams
Ladies 14K rose gold seven-across diamond semi-eternity band with a half-round s...
Category
21st Century and Contemporary Unknown Wedding Rings
Materials
Diamond, 14k Gold, Rose Gold, Gold
Antique Victorian 18K Yellow Gold Old Mine Diamond Three Stone Wedding Band
Located in Great Neck, NY
Beautiful Antique Victorian 18K Yellow Gold Old Mine Diamond Three Stone Wedding Band. This beautiful Victorian three diamond wedding band is crafted in 18k yellow gold. The center h...
Category
Antique 1890s Victorian Wedding Rings
Materials
Diamond, Gold, 18k Gold, Yellow Gold
Natural 1.81 Carat Marquise Shape Diamond Cuff Ring 14 Karat White Gold Jewelry
Located in IN
The marquise diamond is securely set in a lustrous 14 karat white gold cuff, meticulously crafted to enhance its natural beauty and ensure longevity. The white gold setting elegantly...
Category
21st Century and Contemporary Indian Modern Wedding Rings
Materials
Diamond, White Gold, 14k Gold
Bright Pink Red Spinel Milgrain Bezel Set Wedding Band 14K Gold
Located in Osprey, FL
♥ Bright Pink Red Spinel Milgrain Bezel Set Wedding Band 14K Gold
♥ The design measures 4.9mm in length (North South direction), 19.4mm in width...
Category
2010s American Wedding Rings
Materials
Spinel, Gold, 14k Gold, Rose Gold
1.69 carats Ceylon Sapphire ring with diamonds in platinum
Located in PARIS, FR
Stones: 1.69 carats Ceylon Sapphire
and diamonds for a total weight of 0.20 carat.
Material: Platinum
Dimensions: 7 mm length on finger
Weight: 4.8g
Size: 54 (free sizing)
Certificat...
Category
Vintage 1980s Wedding Rings
Materials
Diamond, Sapphire, Platinum
Estate DAVID YURMAN Sterling Silver Amethyst Ring With Diamonds size 7
Located in New York, NY
An estate David Yurman Amethyst ring with diamond accents.
Sterling silver
This beautiful authentic ring is by David Yurman from the his Co...
Category
2010s Engagement Rings
Materials
Diamond, Amethyst, Sterling Silver
Natural 1.81 Carat Marquise Shape Diamond Cuff Ring 18 Karat White Gold Jewelry
Located in IN
Indulge in the epitome of sophistication and luxury with the Natural 1.81 Carat Marquise Shape Diamond Cuff Ring, meticulously crafted in exquisite 18 Karat White Gold. This stunning...
Category
21st Century and Contemporary Indian Modern Wedding Rings
Materials
Diamond, 18k Gold, White Gold
Cober Jewellery “Eternal Forest” Yellow Gold Wedding Bands Rings
Located in OSS, NH
We invite you to see more of our collection from Cober Jewellery at 1stDibs!
You can type Cober Jewellery in the search bar to view more pieces of jewellery at our webshop.
Cober Je...
Category
2010s Dutch Contemporary Wedding Rings
Materials
14k Gold, Yellow Gold
Yellow Gold Diamond Wedding Band - 14k Round Brilliant .32ctw Stackable Ring
Located in Greensboro, NC
Size: 7
Sizing Fee: Down 1 size or up 2 sizes for $35
Metal Content: 14k Yellow Gold & 14k White Gold
Stone Information
Natural Diamonds
Carat(s): .32ctw
Cut: Round Brilliant
Colo...
Category
21st Century and Contemporary Wedding Rings
Materials
Diamond, 14k Gold, White Gold, Yellow Gold
Blue sapphire wedding band 14KT yellow gold
Located in Boca Raton, FL
Cute wedding band made with blue and white sapphires in 14KT yellow gold, size 7, cannot be re-sized.
Metal Type: 14KT
Natural Sapphire(s):
Color:...
Category
21st Century and Contemporary Wedding Rings
Materials
Blue Sapphire, 14k Gold, Yellow Gold
Colombian emerald and old cut diamonds ring from 1900
Located in PARIS, FR
Stones: 0.50 carat Colombian Emerald
and old cut diamonds for a total weight of approximately 1 carat
Material: 18 yellow gold and platinum
Dimensions: 12mm length on finger
Period: ...
Category
Antique Early 1900s Wedding Rings
Materials
Diamond, Emerald, 18k Gold, Platinum
Unique Two-in-One Green Sapphire and Diamond Wedding Ring 14k Solid Yellow Gold
By VR Jewels
Located in Houston, TX
Unique Two-in-One Green Sapphire and Diamond Wedding Ring in 14K Gold featuring natural green sapphire of 0.9 carats and diamonds of ...
Category
21st Century and Contemporary American Art Deco Wedding Rings
Materials
Green Sapphire, Sapphire, Diamond, Yellow Gold, 14k Gold, Gold
Natural Opal and Halo Diamond Wedding Ring in 18k Solid White Gold
By VR Jewels
Located in Houston, TX
Natural Opal and Halo Diamond Wedding Ring in 18K Gold featuring natural opal of 1.24 carats. The gorgeous handcrafted ring goes with every ...
Category
21st Century and Contemporary American Modern Wedding Rings
Materials
Opal, Diamond, White Gold, 18k Gold, Gold
Unisex Two-in-One 14k Solid Yellow Gold Natural Ruby and Diamond Wedding Ring
By VR Jewels
Located in Houston, TX
Unisex Natural Ruby and Diamond Multi Wear Wedding Ring in 14K Gold featuring natural ruby of 0.8 carats and diamonds of 0.25 carats. The gorgeous handcrafted ring goes with every st...
Category
21st Century and Contemporary American Art Deco Wedding Rings
Materials
Ruby, Diamond, Yellow Gold, 14k Gold, Gold
NO RESERVE 0.55CTW Round Diamond Engagement Wedding Ring 14K White Gold
Located in Ramat Gan, IL
FOR US CUSTOMER NO VAT!
This charming engagement diamond ring is adorned with a total of 0.35 carats distributed across 14 diamonds, set delicately in a 14K white gold band. The dia...
Category
21st Century and Contemporary Israeli Art Deco Wedding Rings
Materials
Diamond, 14k Gold, White Gold
Victorian Five Stone No Heat Sapphire 1.6 ctw, Diamond Ring 18k rose gold.
Located in Joelton, TN
Handmade 18K rose gold, 5-stone vivid deep blue violet sapphire and rose cut diamond band. The band measures approximately 3.75mm at the shoulder, tapering to 1.45mm in width at the ...
Category
Antique 1890s European Victorian Wedding Rings
Materials
Diamond, Sapphire, Rose Gold
18 Karat White Gold Diamond Band Ring Size 7 #16119
Located in Washington Depot, CT
Vintage 18K White Gold Diamond Band Ring size 7-
This sparkling band features 23 round brilliant cut diamonds set in beautifully detailed 18K white gold.
Width: 2 mm.
Approximate total diamond weight: .23 ct...
Category
21st Century and Contemporary Wedding Rings
Materials
Diamond, 18k Gold, White Gold
14K Yellow Gold And Diamond Band Ring
Located in Guaynabo, PR
This is a 14K Yellow Gold and Diamond Band Ring. It depicts a wide ribbed band ring with a single round sparkling diamond in gold bezel setting at the center. Its weights is 7 grams ...
Category
20th Century Unknown Modern Wedding Rings
Materials
Diamond, Yellow Gold, 14k Gold
Susan Crow Studio Yellow Gold and Montana Yogo Sapphire Chafee Ring
Located in US
When you look down at the modern Chafee ring, it’s like a little piece of architecture in gold.
Our Chafee ring is named afterJudith Chafee, a Tucson based architect that embraced “r...
Category
21st Century and Contemporary Contemporary Wedding Rings
Materials
Sapphire, 14k Gold, Yellow Gold
TJD 0.20 Carat Diamond and 1.22 Ct Blue Sapphire 18 Karat Yellow Gold Halo Ring
By TJD
Located in New York, NY
This ring dazzles with diamond and blue sapphire. Decorated with shimmering 46 single cut & brilliant cut diamonds and 1 oval blue sapphire set in prong & pave setting. We only use 1...
Category
2010s Indian Modern Wedding Rings
Materials
Blue Sapphire, Diamond, Yellow Gold, 18k Gold, Gold
Vintage Three Stone Diamond Ring 14kt White Gold Old Diamonds Antique
Located in Jupiter, FL
Antique diamond ring in 14KT white gold, ornaments are hand made on the ring.
GRAM WEIGHT: 3.20gr
METAL: 14KT white gold
NATURAL DIAMOND(S)
Cut: Round (old cut)
Color: G
Clarity: ...
Category
Antique 19th Century Unknown Early Victorian Band Rings
Materials
Diamond, 14k Gold, White Gold
TJD 0.25 Carat Baguette & Round Diamond 18 Karat White Gold Twisted Wedding Band
By TJD
Located in New York, NY
This Wide Wedding Band is expertly crafted in 18 Karat white gold and features 40 Round and 5 baguette cut diamonds set in a beautiful design in prong setting. We only use 100% natur...
Category
2010s Indian Contemporary Wedding Rings
Materials
Diamond, White Gold, 18k Gold
5 stone diamond ring
Located in Bangkok, TH
This ring is made with 5 identical sets of Piecut diamonds.
each set consist of 9 specially cut & polished diamonds placed to form a Single Emerald cut diamond.
Invisible set diamonds with no gold visible between the diamonds make it a very special and high level of craftmanship.
Crafted using five sets of beautifully cut diamonds arranged in a row, a 5 stone diamond ring...
Category
2010s Thai Romantic Wedding Rings
Materials
Diamond, 14k Gold, 18k Gold
TJD 0.20 Carat Diamond and 1.22 Ct Blue Sapphire 14 Karat Yellow Gold Halo Ring
By TJD
Located in New York, NY
This ring dazzles with diamond and blue sapphire. Decorated with shimmering 46 single cut & brilliant cut diamonds and 1 oval blue sapphire set in prong & pave setting. We only use 1...
Category
2010s Indian Modern Wedding Rings
Materials
Blue Sapphire, Diamond, 14k Gold, Yellow Gold, Gold
Brilliant Cut Diamond Band Ring Solid 14k White Gold
Located in Honolulu, HI
Item Specifications:
Metal: 14k White Gold
Diamond Count: 20 brilliant cut
Total Diamond Carat Weight: 0.30 carats
Diamond Color: H
Diamond Clarity: SI2-I1
Ring Size: 7
Total...
Category
Late 20th Century Unknown Modern Band Rings
Materials
Diamond, Gold, White Gold, 14k Gold
Genuine Ruby Blossoms Sterling Silver Ring in 925 Sterling Silver for Women
Located in Houston, TX
Introducing our Genuine Ruby Blossoms Ring with Diamonds! Crafted with exquisite detail in sterling silver. This genuine ruby wedding ring embodies elegance and sophistication, makin...
Category
21st Century and Contemporary American Contemporary Wedding Rings
Materials
Ruby, Silver, Sterling Silver
Alexander G VS1 1.30 Carat Princess Cut Diamond Ring 18k White Gold
Located in BEVERLY HILLS, CA
Stunning and classic diamond halo engagement ring.
Center stone was GIA certified but the certificate has been lost, GIA report number 6107639669.
1.97 carats total diamond weight.
...
Category
21st Century and Contemporary American Modern Engagement Rings
Materials
White Diamond, Diamond, White Gold, 18k Gold, Gold
1.03 carats emerald ring with diamonds
Located in PARIS, FR
Stones: Emerald of 1.03cts, 20 diamonds: 0.60ct
Material: Platinum and yellow gold
Dimensions: 1.3cm x 1.1cm
Weight: 4.4g
Period: Art Deco style
Size: 54 (free sizing)
Certificate
Re...
Category
Vintage 1980s Art Deco Wedding Rings
Materials
Diamond, Emerald, 18k Gold, Platinum
TJD 1.0 Carat White & Blue Treated Diamond 14 Karat White Gold Wedding Band Ring
By TJD
Located in New York, NY
Elegantly designed by our skillful artisans in 14 Karat white gold and studded with 109 brilliant cut round white diamond and blue treated diamond in prong setting. Total diamond wei...
Category
2010s Indian Modern Wedding Rings
Materials
Diamond, 14k Gold, White Gold
Natural Oval Ruby Gemstone Ring Diamond 18 Karat White Gold Handmade Jewelry
Located in IN
Surrounding the ruby gemstone are dazzling diamonds, meticulously set in lustrous 18 Karat White Gold. Each diamond is carefully selected for its exceptional quality and brilliance, ...
Category
21st Century and Contemporary Indian Modern Wedding Rings
Materials
Ruby, Diamond, White Gold, 18k Gold
14k Yellow Gold Toi Et Moi Diamond Pear Ring
Located in New York, NY
Can be part of a couples ring, this two stone ring is inspired by the support in a relationship that one gives to each other. So we made this 14K Gold women’s Toi Et Moi Ring, which ...
Category
2010s Fashion Rings
Materials
Diamond, 14k Gold, Yellow Gold
Gin & Grace 14K White Gold Genuine Blue Sapphire Ring with Diamonds for women
Located in New York, NY
Decorate yourself in elegance with this Ring is crafted from 14-karat White Gold by Gin & Grace. This Ring is made up of 7x5 mm Oval-Cut Blue Sapphire (1 pcs) 0.94 carat, Round-cut B...
Category
21st Century and Contemporary Chinese Art Deco Wedding Rings
Materials
Diamond, Blue Sapphire, 14k Gold, White Gold
TJD 0.65 Carat Natural Round Cut Diamond 14 Karat White Gold Bridal Ring Set
By TJD
Located in New York, NY
Make that special moment magical with the exquisite diamond bridal ring set. This classic engagement ring is studded with single cut & brilliant cut 107 diamond in prong setting. Thi...
Category
2010s Indian Modern Wedding Rings
Materials
Diamond, White Gold, 14k Gold
Georgian Style Cushion Cut Diamond Wedding Band with Original Georgian Diamonds
Located in Danvers, MA
This is one of two beautiful Georgian style diamond bands I've created using Georgian period old mine cut/peruzzi cut diamonds from a damaged an...
Category
21st Century and Contemporary American Georgian Wedding Rings
Materials
Diamond, 18k Gold, Sterling Silver
TJD 1.0 Carat Marquise & Brilliant Cut Diamond 18 Karat White Gold Spiral Ring
By TJD
Located in New York, NY
A meaningful symbol of your never ending commitment. The beautiful ring is crafted from 18-karat white gold and features 126 single cut, brilliant cut & marquise diamond set in prong...
Category
2010s Indian Modern Wedding Rings
Materials
Diamond, White Gold, 18k Gold
TJD 0.75 Carat Multi-cut Diamond 18 Karat Gold Pear-Shaped Frame Bridal Ring Set
By TJD
Located in New York, NY
Make that special moment magical with the exquisite diamond bridal ring set. This classic bridal ring is studded with single cut, princess cut, pear & marquise cut 116 diamonds in pr...
Category
2010s Indian Modern Wedding Rings
Materials
Diamond, 18k Gold, Yellow Gold
4mm Wide Rainbow Sapphire Bezel Set Wedding Band 14K Gold
Located in Osprey, FL
♥ 4mm Wide Rainbow Sapphire Bezel Set Wedding Band 14K Gold
♥ The design measures 3.8mm in length (North South direction), 20.5mm in width (East...
Category
2010s American Wedding Rings
Materials
Sapphire, Gold, 14k Gold
TJD 0.75 Carat Multi-cut Diamond 14 Karat Gold Pear-Shaped Frame Bridal Ring Set
By TJD
Located in New York, NY
Make that special moment magical with the exquisite diamond bridal ring set. This classic bridal ring is studded with single cut, princess cut, pear & marquise cut 116 diamonds in pr...
Category
2010s Indian Modern Wedding Rings
Materials
Diamond, 14k Gold, Yellow Gold
TJD 0.65 Carat Natural Round Cut Diamond 18 Karat White Gold Bridal Ring Set
By TJD
Located in New York, NY
Make that special moment magical with the exquisite diamond bridal ring set. This classic engagement ring is studded with single cut & brilliant cut 107 diamond in prong setting. Thi...
Category
2010s Indian Modern Wedding Rings
Materials
Diamond, 18k Gold, White Gold
TJD 1.0 Carat Natural Round & Baguette Diamond Wedding Band Ring in 14Karat Gold
By TJD
Located in New York, NY
Bring charm to your look with this diamond ring. This beautiful ring is crafted in 14KT white gold, and studded with 118 single cut, brilliant cu and baguette cut natural diamonds in...
Category
2010s Indian Contemporary Wedding Rings
Materials
Diamond, 14k Gold, White Gold
Gin & Grace 14K White Gold Mozambique Genuine Ruby Ring with Diamonds for women
Located in New York, NY
Decorate yourself in elegance with this Ring is crafted from 14-karat White Gold by Gin & Grace. This Ring is made up of 7x5 mm Oval-Cut Ruby (1 pcs) 1.00 carat, Round-cut Hot Pink R...
Category
21st Century and Contemporary Chinese Art Deco Wedding Rings
Materials
Diamond, Ruby, 14k Gold, White Gold
TJD 1.0 Carat Brilliant Cut Diamond Wedding Band Ring in 14 Karat Yellow Gold
By TJD
Located in New York, NY
Truly exquisite, this diamond engagement band is sure to be admired for the inherent classic beauty and elegance within its design. The total weight of diamonds 1.0 carat, H-I color,...
Category
2010s Indian Contemporary Wedding Rings
Materials
Diamond, 14k Gold, Yellow Gold
TJD 1.50 Carat Natural Diamond Vintage-Style Wedding Band Ring in 14 Karat Gold
By TJD
Located in New York, NY
Truly exquisite, this diamond engagement band is sure to be admired for the inherent classic beauty and elegance within its design. This ring is beautifully crafted in 14 Karat white...
Category
2010s Indian Contemporary Wedding Rings
Materials
Diamond, 14k Gold, White Gold
TJD 1.50 Carat Brilliant cut Diamond 14 Karat White Gold Wedding Band Ring
By TJD
Located in New York, NY
This beautiful engagement band ring features shimmering brilliant cut round diamonds in nic & pave setting. Crafted in 14 karat white gold. The ring is studded with a total of 43 bri...
Category
2010s Indian Contemporary Wedding Rings
Materials
Diamond, 14k Gold, White Gold
TJD 0.50 Carat Natural Round Diamond 14 Karat White Gold Wedding Band Ring
By TJD
Located in New York, NY
Truly exquisite, this diamond engagement band is sure to be admired for the inherent classic beauty and elegance within its design. The total weight of diamonds 0.50 carat, H-I color...
Category
2010s Indian Contemporary Wedding Rings
Materials
Diamond, 14k Gold, White Gold
NO RESERVE 0.40CT Solitaire Engagement Diamond Ring 14K White Gold
Located in Ramat Gan, IL
FOR US CUSTOMER NO VAT!
This elegant ring features a dazzling 0.40 carat diamond with exceptional clarity VS2 and a brilliant. The diamond is set in a classic 14K white gold band, a...
Category
21st Century and Contemporary Israeli Art Deco Wedding Rings
Materials
White Diamond, Diamond, White Gold, 14k Gold
White Gold Diamond Enhancer Wedding Band - 14k Round Brilliant .25ctw Guard Ring
Located in Greensboro, NC
Size: 7
Sizing Fee: Up 2 sizes for $35 or Down 1 size for $35
Metal Content: 14k White Gold
Stone Information
Natural Diamonds
Carat(s): .25ctw
Cut: Round Brilliant
Color: G - H
Cl...
Category
21st Century and Contemporary Wedding Rings
Materials
Diamond, 14k Gold, White Gold
Wedding Band Ring Engagement Ring Name Gold Ruby Diamond Emerald
By J DAUPHIN
Located in Los Angeles, CA
Wedding or Engagement Ring with Personalized Custom Engraved or Letters in relief
This Price indicate Ring in 14K Yellow Gold with Ruby if nothing else is requested
GEMS: Can be m...
Category
2010s American Contemporary Engagement Rings
Materials
Yellow Sapphire, Pink Sapphire, Blue Sapphire, Ruby, Emerald, Black Diam...
0.70 ct Oval Cut Diamond Solitaire, Diamond Solitaire Ring with Edge Stone, Quee
Located in ISTANBUL, TR
0,70 ct Oval Cut Diamond Solitaire Ring, GIA Certified Diamond Ring
HRD Certified Diamond Wedding Ring,Solitaire Ring
This ring was made with quality materials and excellent handwor...
Category
2010s Turkish Wedding Rings
Materials
Diamond, 14k Gold
GIA Certified 3.16 Carat Oval Cut Blue Sapphire and Natural Diamond Ring ref937
By Diamond Town
Located in New York, NY
Featuring a GIA Certified 3.16 carat oval-cut blue Ceylon sapphire at its center, flanked by two oval-cut diamonds with a total diamond weight of 0.87 carats, this ring exudes radian...
Category
21st Century and Contemporary Contemporary Three-Stone Rings
Materials
Blue Sapphire, Sapphire, White Diamond, Diamond, White Gold, 18k Gold
8mm Wide 14K / 18K Solid Gold Cigar Wedding Ring
Located in Hertsliya, IL
This 8mm wide band, featuring a flat profile, is crafted from your choice of 14k or 18k solid gold. Known as the 'cigar band,' it exudes sophistication and enduring style, a perfect ...
Category
2010s Modern Wedding Rings
Materials
Gold, 14k Gold, Rose Gold, White Gold, Yellow Gold
Antique Platinum 1920’s Band Ring
Located in Brighton, GB
Antique Platinum Band
Circa 1920’s
Lovely, platinum stamped band. Decorated with alternating floral & plain sections all the way around. Stampe...
Category
Early 20th Century English Wedding Rings
Materials
Platinum