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Buy Round Shape 12 mm Gems

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Gemtype Color Shape Weight Size Clarity Price Origin
You Selected (584): Round Shape 12 mm Gems Clear All
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Brown Smoky Quartz Gem - 5.2ct Round Checkerboard (double sided) (ID: 416678)

Round Brown Smoky Quartz

5.2ct
12.1 mm
$ 7.76
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1 pc
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Silver Pearl Gem - 13ct Spherical (ID: 338171)

Sphere / Ball Gray Pearl

13ct
12.1 mm
$ 129.70
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Grayish Silver Star Sapphire Gem - 11ct Round Cabochon (ID: 470800)

Round Gray Star Sapphire

11ct
11.5 mm
$ 383.95
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2 pcs
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Green Prehnite Gem - 5.8ct Round Facet (ID: 248654)

Round Green Prehnite

5.78 ct (total 11.55ctw)
12 mm
$ 51.98
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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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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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White Quartz Cat's Eye Gem - 7.8ct Round Cabochon (ID: 360634)

Round White Quartz Cat's Eye

7.8ct
11.8 mm
$ 31.08
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Green Maw-Sit-Sit Gem - 6.6ct Round Cabochon (ID: 397238)

Round Green Maw-Sit-Sit

6.6ct
11.6 mm
$ 19.86
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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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2 pcs
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Green Jadeite Gem - 6.8ct Round Cabochon (ID: 470604)

Round Green Jadeite

6.84 ct (total 13.68ctw)
11.7 mm
$ 41.04
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Golden Pearl Gem - 13ct Spherical (ID: 335849)

Sphere / Ball Yellow Pearl

13ct
12.3 mm
$ 265.74
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Silver Pearl Gem - 13.3ct Spherical (ID: 338211)

Sphere / Ball Gray Pearl

13.3ct
12.3 mm
$ 199.50
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Swiss Blue Topaz Gem - 9.9ct Round Concave Fantasy Cut (ID: 486154)

Round Blue Topaz

9.9ct
11.9 mm
$ 88.74
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2 pcs
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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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Silver Pearl Gem - 13ct Spherical (ID: 338212)

Sphere / Ball Gray Pearl

13ct
12.3 mm
$ 195.60
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2 pcs
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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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Multicolor Coral Gem - 5.5ct Round Cabochon (ID: 515795)

Round Multicolor Coral

5.5ct
12.1 mm
$ 15.78
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White Quartz Cat's Eye Gem - 8.4ct Round Cabochon (ID: 360624)

Round White Quartz Cat's Eye

8.4ct
12.2 mm
$ 33.56
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2 pcs
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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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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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Deep Brown Cat's Eye Scapolite Gem - 9.1ct Round Cabochon (ID: 470428)

Round Brown Cat's Eye Scapolite

9.1ct
11.8 mm
$ 45.70
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
man their gems are pretty good, and the prices aren't to bad either, I like checking out hte gems on there website, beceause the pictures of the gems are taken pretty well, and you can see the table, and the facets.
Posted By Spinach in March, 2019
Source: Bizrate
Overall Rating -> 10 star ratings
I love gemselect and I have bought a fair amount from them. The only complaint I have is not being able to save gems. I have a lot of projects so i am in the market for a lot of different gems and it's so disappointing to have to delete them all just to purchase one or two that I have saved in my cart.
Posted By S.Hicks in March, 2019
Source: Bizrate
Overall Rating -> 10 star ratings
I always check this site because they have unique options.
Posted By Lisa in February, 2019
Source: Bizrate
Overall Rating -> 10 star ratings
Great website to navigate. Awesome Gem selection! Nice photos and discriptions for all of the gems for sale. You can find gems in all price ranges. Checkout was a breeze.
Posted By Timmy in February, 2019
Source: Bizrate
Overall Rating -> 10 star ratings
They had an extensive gemstone selection in all different cuts, sizes, and colors. They also had very good and workable prices. All of these aspects pulled me in as a customer.
Posted By Josh in February, 2019
Source: Bizrate
Overall Rating -> 9 star ratings
It all depend on the product I will receive and have it verified by my in law jewellers.
Posted By Vodka in February, 2019
Source: Bizrate
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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