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Buy Round Shape 12 mm Gems

(615)
Gem Type Weight Size Clarity Price Origin
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Deep Blue Kyanite Gem - 15.8ct Drilled Sphere (ID: 447301)

Sphere / Ball Blue Kyanite

15.79 ct (total 31.57ctw)
11.9 mm
$ 63.14
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2 pcs
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Brownish Green Jadeite Gem - 8ct Round Cabochon (ID: 470588)

Round Green Jadeite

8.04 ct (total 16.07ctw)
12.2 mm
$ 48.21
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Sky Blue Larimar Gem - 6.4ct Round Cabochon (ID: 505534)

Round Blue Larimar

6.38 ct (total 12.76ctw)
12.2 mm
$ 80.64
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1 pc
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Dark Grey Pearl Gem - 13ct Spherical (ID: 338171)

Sphere / Ball Gray Pearl

13ct
12.1 mm
$ 129.70
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Medium Orange Sunstone Gem - 5.8ct Round Facet (ID: 511212)

Round Orange Sunstone

5.8ct
12 mm
$ 57.70
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1 pc
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Dark Chocolate Brown Cat's Eye Scapolite Gem - 8.2ct Round Cabochon (ID: 470427)

Round Brown Cat's Eye Scapolite

8.2ct
11.6 mm
$ 41.15
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White Quartz Cat's Eye Gem - 8.5ct Round Cabochon (ID: 360619)

Round White Quartz Cat's Eye

8.5ct
12.1 mm
$ 33.92
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2 pcs
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Black Spinel Gem - 6.3ct Round Rose-Cut (ID: 438498)

Round Black Spinel

6.32 ct (total 12.64ctw)
11.9 mm
$ 37.92
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2 pcs
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Grayish Moss Green Jadeite Gem - 8.1ct Round Cabochon (ID: 470598)

Round Green Jadeite

8.06 ct (total 16.12ctw)
12.1 mm
$ 48.36
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Warm White Cat's Eye Moonstone Gem - 7.3ct Round Cabochon (ID: 481796)

Round White Cat's Eye Moonstone

7.3ct
11.8 mm
$ 29.36
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Mossy Green Jadeite Gem - 7.1ct Round Cabochon (ID: 470592)

Round Green Jadeite

7.14 ct (total 14.28ctw)
11.9 mm
$ 42.84
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Light Grey Star Sapphire Gem - 11ct Round Cabochon (ID: 470800)

Round Gray Star Sapphire

11ct
11.5 mm
$ 383.95
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Blue-Green Silver  Pearl Gem - 13ct Spherical (ID: 338212)

Sphere / Ball Gray Pearl

13ct
12.3 mm
$ 195.60
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Silver  Pearl Gem - 13.6ct Spherical (ID: 338281)

Sphere / Ball Gray Pearl

13.6ct
12.4 mm
$ 204.30
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Aqua Blue Larimar Gem - 6.8ct Round Cabochon (ID: 505437)

Round Blue Larimar

6.8ct
12 mm
$ 43.23
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Medium-Dark Grey Pearl Gem - 13.3ct Spherical (ID: 338211)

Sphere / Ball Gray Pearl

13.3ct
12.3 mm
$ 199.50
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2 pcs
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Light Greenish Blue Larimar Gem - 6.1ct Round Cabochon (ID: 505530)

Round Blue Larimar

6.09 ct (total 12.17ctw)
12 mm
$ 76.91
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White Topaz Gem - 7.1ct Round Facet (ID: 376428)

Round White Topaz

7.1ct
11.7 mm
$ 49.91
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Medium Violet Amethyst Gem - 5.8ct Round Facet (ID: 459466)

Round Violet Amethyst

5.8ct
11.8 mm
$ 34.92
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Golden Orange Citrine Gem - 6.1ct Round Facet (ID: 501186)

Round Golden Citrine

6.1ct
12 mm
$ 42.49
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2 pcs
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Multicolor Jasper Gem - 12.4ct Drilled Sphere (ID: 361817)

Sphere / Ball Multicolor Jasper

12.41 ct (total 24.81ctw)
12.3 mm
$ 24.81
Item in Stock
Round Shape 12 mm Gems

Some people by gems by color or price, but for many, it is best to buy gems by shape and size - especially if you're in need of a gem to replace a previous item that was lost or damaged. Calibrated Round shapes, facet cut and cabochon gems available now in 12 mm diameter size range. Shop a wide range of calibrated gemstones by size online at wholesale from GemSelect.

As a general guideline, when it comes to 'calibrated' gems, they are not usually expected to be cut to exact measurements. For calibrated gemstones weighing under one carat, most jewelry settings will accommodate a gem which is within 0.2 mm of the calibrated size in order to fit a standard setting. For gemstones that weigh over one carat, a larger variance is acceptable, often around 0.3 mm or slightly higher even. This small variance can usually be accommodated for standard style settings. Round-cut gemstones should also have a greater variance in acceptable size when it comes to calibration; in fact it is usually possible to mount a round stone of any size in the closest standard setting.

Certified Customer Reviews
Overall Rating -> 10 star ratings
GemSelect has a wonderful well described selection that surprises me how quickly it ships.
Posted By Tim in December, 2019
Source: Bizrate
Overall Rating -> 10 star ratings
They have the best selection of different gems and the prices and fantastic
Posted By Brandi in December, 2019
Source: Bizrate
Overall Rating -> 9 star ratings
Very clear site. The photos and video make sure you know exactly what you are getting. I also appreciate all of the additional info. and definitions/explanations offered
Posted By NuthinClever in December, 2019
Source: Bizrate
Overall Rating -> 10 star ratings
Working on a special anniversary gem collection for my wife, and was able to find almost everything on this one site. Having bought from yall before, this was a no-brainer on where to go for the right stones/buying experience.
Posted By ESP in December, 2019
Source: Bizrate
Overall Rating -> 10 star ratings
Great products and very customer friendly. Will be purchasing again. Thanks!
Posted By Joe in December, 2019
Source: Bizrate
Overall Rating -> 9 star ratings
You have a much wider variety of stones than other dealers. I come back for this reason: lots and lots of everything.
Posted By G in December, 2019
Source: Bizrate
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More Shapes
  • Asscher Cut
  • Baguette / Scissor Cut
  • Baguette Cabochon
  • Baguette Checkerboard
  • Baguette Crystal Cluster
  • Baguette Facet
  • Baguette Rose-Cut
  • Baguette Step Cut
  • Baguette Sugarloaf Cabochon
  • Baroque
  • Barrel
  • Barrel / Checkerboard
  • Barrel / Full-Round
  • Barrel / Scissor Cut
  • Barrel Cabochon
  • Barrel Rose Cut
  • Bear Carving with Hole
  • Bird Carving
  • Briolette with Hole
  • Carved Baguette
  • Carved Cameo
  • Carved Cushion
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  • Carved Fancy
  • Carved Fish
  • Carved Fish with Hole
  • Carved Flower
  • Carved Fruit
  • Carved Half Heart
  • Carved Half Moon
  • Carved Heart
  • Carved Heart Cabochon
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  • Carved Octagon
  • Carved Oval
  • Carved Oval Cabochon
  • Carved Owl
  • Carved Pear
  • Carved Pear Cabochon
  • Carved Rhomb
  • Carved Rose
  • Carved Rose with Half Drilled Hole
  • Carved Round
  • Carved Round Cabochon
  • Carved Sheep
  • Carved Shell
  • Carved Square
  • Carved Teardrop
  • Carved Trillion
  • Carved Turtle
  • Cushion Buff-Top
  • Cushion Cabochon
  • Cushion Carved Medusa Cameo
  • Cushion Checkerboard
  • Cushion Checkerboard (double sided)
  • Cushion Concave Fantasy Cut
  • Cushion Crystal Cluster
  • Cushion Mixed Cut
  • Cushion Rose-Cut
  • Cushion Shape Sugarloaf Cabochon
  • Cushion Sugarloaf Cabochon
  • Cushion-Cut
  • Diamond-Cut
  • Drilled Faceted Sphere
  • Drilled Sphere
  • Drilled Square Rondelle Slice
  • Drop / Pear
  • Fancy Cabochon
  • Fancy Carved Cushion
  • Fancy Carved Oval
  • Fancy Carved Pear
  • Fancy Carved Round
  • Fancy Carved Trillion
  • Fancy Carving
  • Fancy Crystal Cluster
  • Fancy Facet
  • Fancy Fantasy Carved Leaf
  • Fancy Fantasy Carving
  • Fancy Slice
  • Fancy Star Facet
  • Fancy-Cut
  • Fantasy Carved Flower
  • Fantasy Carved Flower Cut
  • Fantasy Carved Leaf
  • Flower Carving
  • Flower-Cut
  • Half Heart Cabochon
  • Half Heart Facet
  • Half Moon Cabochon
  • Half Moon Facet-Cut
  • Half Moon Faceted
  • Half-Drilled Briolette
  • Half-Drilled Heart Checkerboard Facet
  • Half-Drilled Sphere
  • Heart Cabochon
  • Heart Checkerboard (double sided)
  • Heart Facet
  • Heart Rose-Cut
  • Hexagon Cut
  • Marquise Buff-Top
  • Marquise Cabochon
  • Marquise Checkerboard
  • Marquise Checkerboard (double sided)
  • Marquise Facet
  • Marquise Mixed Cut
  • Marquise Slice
  • Marquise Sugarloaf Cabochon
  • Octagon / Scissor Cut
  • Octagon Cabochon
  • Octagon Checkerboard
  • Octagon Facet
  • Octagon Step Cut
  • Oval Buff-Top
  • Oval Cabochon
  • Oval Cabochon with Hole
  • Oval Carved Cameo
  • Oval Checkerboard
  • Oval Checkerboard (double sided)
  • Oval Concave Cut
  • Oval Crystal Cluster
  • Oval Diamond-Cut
  • Oval Facet
  • Oval Fancy Facet
  • Oval Fantasy Concave Cut
  • Oval Mixed Cut
  • Oval Portuguese-Cut
  • Oval Rose-Cut
  • Oval Slice
  • Pear Cabochon
  • Pear Checkerboard
  • Pear Checkerboard with Hole
  • Pear Concave Cut
  • Pear Concave Fantasy Cut
  • Pear Crystal Cluster
  • Pear Double-Sided Checkerboard
  • Pear Facet
  • Pear Shape Sugarloaf Cabochon
  • Pear Slice
  • Pencil
  • Pencil Cut
  • Pentagon Facet
  • Princess-Cut
  • Rhomb Cabochon
  • Rhomb Checkerboard
  • Rhomb Checkerboard (Double-Sided)
  • Rhomb Facet
  • Rondelle
  • Round Buff-Top
  • Round Cabochon
  • Round Carved Cameo
  • Round Checkerboard
  • Round Checkerboard (double sided)
  • Round Concave Cut
  • Round Concave Fantasy Cut
  • Round Drilled Checkerboard (Double Sided)
  • Round Drilled Rondelle
  • Round Facet
  • Round Mixed Cut
  • Round Mixed-Cut
  • Round Petal Cut
  • Round Portuguese-Cut
  • Round Rose-Cut
  • Round Rose-Cut (double sided)
  • Shark Fin Cabochon
  • Shield Cabochon
  • Shield Checkboard
  • Spherical
  • Square / Scissor Cut
  • Square Cabochon
  • Square Facet
  • Square Rose-Cut
  • Square Step-Cut
  • Square Sugarloaf Cabochon
  • Square with Hole
  • Tapered Baguette
  • Tapered Baguette Cabochon
  • Teardrop Cabochon
  • Trapezoid
  • Trapezoid Cabochon
  • Trapezoid Checkerboard
  • Triangle
  • Triangle Cabochon
  • Trillion Cabochon
  • Trillion Checkerboard
  • Trillion Concave Cut
  • Trillion Concave Fantasy Cut
  • Trillion Crystal Cluster
  • Trillion Facet
  • Trillion Rose-Cut
  • Trillion Shape Sugarloaf Cabochon
  • Undrilled Briolette Teardrop
Popular Gemstones
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  • Tanzanite
All Gemstones (144)
A B C D E F G H I J K L M N O P Q R S T V Z
  • Actinolite Cat's Eye
  • Agate
  • Agate Geode
  • Almandine Garnet
  • Amazonite
  • Amethyst
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  • Ammolite
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  • Andesine Labradorite
  • Apatite
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  • Aventurine
  • Beryl
  • Black Opal
  • Bloodstone
  • Boulder Opal
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  • Demantoid Garnet
  • Dendritic Agate
  • Diamond
  • Druzy Amethyst
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  • Emerald
  • Enstatite
  • Fire Agate
  • Fire Opal
  • Fluorite
  • Fossil Coral
  • Garnet
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  • Grossularite Garnet
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  • Hiddenite
  • Howlite
  • Idocrase
  • Imperial Topaz
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  • Sillimanite Cat's Eye
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Size and Weight

Gems are always measured in Millimeter (mm)

Dimensions are given as;
length x width x depth,
except for round stones which are;
diameter x depth

Select gems by size, not by weight!
Gem varieties vary in density, so carat weight is not a good indication of size

Note: 1ct = 0.2g

Size Comparison Chart