Buy 12 mm Round Calibrated Gemstones from GemSelect

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.

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Overall Rating -> 10

Found what I was looking for

Posted By Rian in June, 2023

Source: Bizrate

Overall Rating -> 10

Wonderful selection of gems to choose from. Have made many purchases and was only slightly disappointed once.

Posted By Teemo in February, 2024

Source: Bizrate

Overall Rating -> 10

Extremely easy to use, and I am fully satisfied with the purchase process.

Posted By Fl_Beachcomber in October, 2023

Source: Bizrate

Overall Rating -> 10

I really enjoy browsing through GemSelect. The selection is always marvelous and I love how detailed everything is described. The only thing I noticed is that when browsing through my phone, the videos of the gems do not load. If there were more videos of the gems, that would be amazing, though I understand that is a lot of work on GemSelect's part! Checking out is also very fast and easy, and I love that the return policy is very good, though I hope I don't have to use it anytime soon.

Posted By ChiChi in January, 2024

Source: Bizrate

Overall Rating -> 10

Excellent experience!

Posted By Steph in April, 2023

Source: Bizrate

Overall Rating -> 10

I have used this site for sseveral years now. All has been great. I started collection gems from GemSelect for years and wanted to collect at least one of most stones. I loved Safers because the mols is a 9 + and they come in every color. This is the best place to buy gems for the assortment and price. Great place to learn about gems too. Sometimes the shipping is a little on the long side. But I would give them a 9.9 out of 10 !!

Posted By Steve in July, 2023

Source: Bizrate

Overall Rating -> 10

My last experience was good, in fact every experience I have had with them has met my expectations or surpassed them. These are really good people to work with.

Posted By Spinach in May, 2023

Source: Bizrate

Overall Rating -> 10

Had a problem ordering first time. Someone from Gem Select reached out to me and cleared problem and I made purchase.

Posted By Myrtle in February, 2024

Source: Bizrate

Overall Rating -> 9

So many gorgeous stones! The only "complaint" I have is it's difficult to visualize sizes in mm. Perhaps some way to compare in inches?It has been a long time since I bought stones from Gem select, but the process wasn't too difficult.

Posted By Ktreva52 in February, 2024

Source: Bizrate

Overall Rating -> 10

I find the website user friendly.

Posted By Becky in August, 2023

Source: Bizrate

Overall Rating -> 9

I have been buy from you for years

Posted By JohnA in May, 2023

Source: Bizrate

Overall Rating -> 10

The gem stone always has a great selection of beautiful stones. The calibrated stone fit my ring perfectly. Thank you gem select !

Posted By Jen in August, 2023

Source: Bizrate

Overall Rating -> 9

The selection and filtering is a little overwhelming, but that's only because there is so much to choose from.

Posted By Kasper in June, 2023

Source: Bizrate

Overall Rating -> 10

GemSelect has the Best gems. Clear photos and detailed description helps me make the best choice. I have Never been disappointed by thier quality items.

Posted By Rock Hound in July, 2023

Source: Bizrate

Overall Rating -> 10

Todo muy bien en la compra ahora esperar recibir el pedido.

Posted By MAGSMX in August, 2023

Source: Bizrate

Gemstones A-Z

Buy Round Shape 12 mm Gems

2.68 carat Orange Hessonite Garnet, Oval loose Hessonite Garnet from Madagascar, Natural Untreated Gem, 9.1 x 7.6 mm

13.41 carat Black Tourmaline, Emerald Cut loose Tourmaline from Mozambique, Natural Untreated Gem, 14.8 x 12.3 mm

7.84 ct Flower Cut Smoky Quartz, 13.1 x 12.7 mm From Brazil

11.2 carat Oval Dendritic Agate, loose Certified Dendritic Agate from India, Natural Untreated Gem, 22.4 x 16 mm

1.96 carat Heart Pyrope Garnet, loose Certified Pyrope Garnet from Mozambique, Natural Untreated Gems, 6.1 x 6.1 mm

0.84 carat Blue Sapphire, Cushion loose Sapphire from Madagascar, Natural Gem, 4.9 x 4.9 mm

3.17 carat Yellow Citrine, Oval loose Citrine from Brazil, Natural Untreated Gem, 10.8 x 8.8 mm

0.25 ct Baguette Cut Kornerupine, 5.4 x 2.7 mm From Sri Lanka

20.11 carat Bi-color Ametrine, Trillion-Cut loose Ametrine from Brazil, Natural Untreated Gem, 18.5 x 16.8 mm

1.88 ct Round Cut Strawberry Quartz, 8.1 mm From Russia

1.08 ct Blue Kyanite, 7 x 4.9 mm Oval Cut From Nepal

0.48 ct Loose Orange Sapphire, 5.7 x 4 mm Oval Cut From Tanzania

6.53 carat Swiss Blue Topaz, Marquise-Cut loose Topaz from Brazil, Natural Gems, 15.6 x 7.9 mm

0.69 ct Loose Yellow Sapphire, 4.6 x 4.6 mm Heart Cut From Tanzania

1.98 carat Orange Zircon, Oval loose Zircon from Tanzania, Natural Untreated Gem, 8 x 6.1 mm

0.75 carat Green Sapphire, Cushion loose Sapphire from Tanzania, Natural Gem, 4.7 x 4.6 mm

0.3 carat Round Ruby, loose Certified Ruby from Myanmar, Natural Gem, 3.7 mm

8.34 ct Round Quartz Cat's Eye, 12.4 mm From India

1.33 carat Emerald Cut Amethyst, loose Certified Amethyst from Brazil, Natural Untreated Gem, 6.9 x 6.9 mm

5.78 ct Marquise Slice Ruby in Fuchsite, 19.6 x 10.2 mm From Ethiopia

27.74 carat Ammolite, loose Certified Ammolite from Canada, Natural Gem, 29.5 x 19.4 mm

0.81 ct Loose Pink Sapphire, 5.1 x 4.1 mm Oval Cut From Madagascar

8.94 ct Yellow Quartz, 15.1 x 15 mm Carved From Brazil

1.19 ct Round Checkerboard Smoky Quartz, 7.1 mm From Brazil

20.53 carat Cushion Amethyst, loose Certified Amethyst from Brazil, Natural Untreated Gem, 18.1 x 18 mm

4.75 ct Oval Cut Strawberry Quartz, 14.1 x 9.9 mm From Russia

4.34 ct Oval Spectrolite, 10.2 x 8.1 mm From Finland

0.9 carat Green Sapphire, Cushion loose Sapphire from Madagascar, Natural Gem, 5.8 x 4.9 mm

0.54 ct Loose Orange Sapphire, 5.6 x 3.9 mm Oval Cut From Tanzania

2.94 ct Oval Cat's Eye Scapolite, 8.2 x 7.2 mm From Madagascar

1.61 carat Oval Demantoid Garnet, loose Certified Demantoid Garnet from Namibia, Natural Untreated Gems, 3.7 x 3 mm

0.71 ct Yellow Sphalerite, 5 mm Round Cut From Spain

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