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

I was looking for ammolite for my husband. Other websites are not always clear about whether they have genuine ammolite or simulated ammolite. I have purchased from GemSelect before and trust that the stones are genuine. Finding the stones I want is easy, and I love all of the search filter options!

Posted By Ana in September, 2023

Source: Bizrate

Overall Rating -> 7

I placed order#384714 based on the picture on your website and the stone came in much darker. I'm sure it's the same stone i ordered but your lighting made it seem a lighter blue. I was trying to match a stone for a customer and based on the picture it would have been close enough but the stone in person is a mile off.

Posted By Bobk in February, 2024

Source: Bizrate

Overall Rating -> 9

Never bought anything on this website before, but it probably won't be my last purchase. Definitely one of the easiest to use and most informative sites I've ever been to.

Posted By Bob in November, 2023

Source: Bizrate

Overall Rating -> 10

Easy to use as always and in all steps from opening site to paying.

Posted By Pete in February, 2024

Source: Bizrate

Overall Rating -> 10

I have used GemSelect for several years and plan to shop more in the further. This is a good source of information on gemstones. I love looking at and learning about them. Lot more than I ever knew existed.

Posted By Bikerwalrus in October, 2023

Source: Bizrate

Overall Rating -> 10

I had a great time searching all the lovely stones. This is my first precious loose stone purchase for my own work. I chose sapphire, and found some lovely briolettes. I wanted 3, but this set of 4 was perfect. Everything was quick and easy, and I'm excited.

Posted By Phoenix in February, 2024

Source: Bizrate

Overall Rating -> 10

My overall interaction with your website was pleasant, as always.

Posted By RJ in April, 2024

Source: Bizrate

Overall Rating -> 8

Very easy to find the specific stone I was looking for. I am pleased by both the selection and the price of the stones that are available. The only "bad" thing that I have to say is that the interface of the site is outdated.

Posted By Nick in March, 2024

Source: Bizrate

Overall Rating -> 10

The website is well organized and works fast forward and back. Plenty of filters. Each gem is described in detail and you receive the one pictured. Gem material info and sources available. I would like to see more specifics on sources besides country- at least region or state and in the US with Turquiose which mine. Thanks!

Posted By Orchidisle in February, 2024

Source: Bizrate

Overall Rating -> 10

Gem Select has gems at afffordable prices.

Posted By George in March, 2024

Source: Bizrate

Overall Rating -> 10

Pleasant.

Posted By Mk in November, 2023

Source: Bizrate

Overall Rating -> 9

Never bought anything on this website before, but it probably won't be my last purchase. Definitely one of the easiest to use and most informative sites I've ever been to.

Posted By Bob in November, 2023

Source: Bizrate

Overall Rating -> 10

Very pleased with shopping on this site. It's easy to navigate and information about gemstones is very good.

Posted By Kate in December, 2023

Source: Bizrate

Overall Rating -> 10

I have used Gem Select many times over the past 10 years and have always been happy with the product & services

Posted By Ordain in August, 2023

Source: Bizrate

Overall Rating -> 10

great. thank you

Posted By Carrotroller in July, 2023

Source: Bizrate

Gemstones A-Z

Buy Round Shape 12 mm Gems

3.17 carat Carved Leaf Pyrope Garnet, loose Certified Pyrope Garnet from Mozambique, Natural Untreated Gem, 11.5 x 8.7 mm

2.02 carat Swiss Blue Topaz, Fancy-Cut loose Topaz from Brazil, Natural Gems, 7.3 x 5.2 mm

6.45 ct Carved Prehnite, 17.2 x 11.5 mm From South Sea

1.82 ct Orange Sunstone, 9.1 x 7.4 mm Oval Cut From India

8.72 ct Oval Tiger's Eye, 16.4 x 12.5 mm From India

0.79 ct Pink Morganite, 6.8 x 4.8 mm Oval Cut From Afghanistan

4.29 ct Oval Spectrolite, 10.2 x 8.2 mm From Finland

0.32 ct Loose Yellow Sapphire, 3.8 x 3.8 mm Princess Cut From Tanzania

3.67 ct Round Prehnite, 7.3 mm From South Africa

41.22 ct Loose Oval Bloodstone, 28.6 x 21.2 mm From Madagascar

7.98 ct Round Rutile Quartz, 13 mm From India

0.71 carat Heart Tsavorite Garnet, loose Certified Tsavorite Garnet from Tanzania, Natural Untreated Gem, 6.7 x 5.8 mm

26.39 carat Oval Amethyst, loose Certified Amethyst from Brazil, Natural Untreated Gem, 22.7 x 14.4 mm

4.79 carat Yellow Citrine, Oval loose Citrine from Brazil, Natural Untreated Gem, 12.3 x 10 mm

3.89 carat Marquise Cut Pyrope Garnet, loose Certified Pyrope Garnet from Mozambique, Natural Untreated Gems, 12 x 6 mm

1.75 carat Oval Opal, loose Certified Opal from Ethiopia, Natural Gems, 8.2 x 6.2 mm

18.38 carat Blue Topaz, Oval loose Topaz from Brazil, Natural Gem, 19.1 x 13.9 mm

12.02 ct Oval Buff Top Chalcedony, 14 x 10 mm From Brazil

23.63 carat Pear Jasper, loose Certified Jasper from the United States, Natural Untreated Gem, 23 x 17.3 mm

3.07 carat Swiss Blue Topaz, Pear Shape loose Topaz from Brazil, Natural Gems, 6 x 4.1 mm

4.13 ct Oval Cat's Eye Opal, 10.8 x 9.3 mm From Madagascar

0.31 ct Oval Cut Kornerupine, 4.8 x 3.4 mm From Sri Lanka

4.7 ct Yellow Quartz, 10 x 8.1 mm Oval Checkerboard From Brazil

0.56 carat Blue Tanzanite, Oval loose Tanzanite from Tanzania, Natural Gem, 6.1 x 4 mm

17.83 carat Black Tourmaline, Oval loose Tourmaline from Mozambique, Natural Untreated Gem, 19.1 x 14.7 mm

0.83 carat Bi-color Sapphire, Cushion loose Sapphire from Madagascar, Natural Gem, 6.1 x 4.8 mm

1.53 ct Blue Apatite, 5.7 x 3.9 mm Oval Cut From Madagascar

1.78 carat Marquise Cut Amethyst, loose Certified Amethyst from Brazil, Natural Untreated Gem, 11.7 x 6 mm

17.98 ct Oval Rose Quartz, 17.6 x 14.9 mm From South Africa

3.58 carat Black Tourmaline, Emerald Cut loose Tourmaline from Mozambique, Natural Untreated Gem, 14.3 x 6 mm

4.45 ct Oval Smoky Quartz, 7.8 x 5.7 mm From Brazil

3 carat Pink Tourmaline, Oval loose Tourmaline from Mozambique, Natural Untreated Gems, 8.1 x 6.1 mm

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