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

Super easy to do business for great products.

Posted By BoBBy in January, 2024

Source: Bizrate

Overall Rating -> 10

I love the clear description of the certification options. It's very rare to see a gem site that offers a deep explanation of each institution that would certify the stone(s).

Posted By Oakcityceo in May, 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 -> 8

Found on a search engine. Scanned inventory and made a small purchase.

Posted By Ralli in August, 2023

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Overall Rating -> 10

I particularly like information about product provided with purchase.

Posted By Dick in May, 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 love GemSelect, photos and details are great.

Posted By #1 in February, 2024

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

It was easy to search and find what i wanted

Posted By Gunner in November, 2023

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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 -> 9

over the experience was similar to other sites i have used. The only real note I have is the checkout experience was tedious and discriminatory, i wouldn't accept visa gift cards, which not only have guaranteed funds but help protect from misuse of personal information, but would not accept my visa b/c it is a prepaid card. I don't have bank account and I have been using the prepaid card for years without issue so this was disappointing to me. I feel safer using reputable gem sites rather than amazon or ebay (I have been sold fake gems with fake certs on both), but not being able to use my own valid legitimate funds and having to find a friend to buy for me b/c I use a non-bank card like 40% of the country is insulting.

Posted By Iggywiggly in January, 2024

Source: Bizrate

Overall Rating -> 10

Fine. All emails answered. Excellent service. Nice discount added for orders. Briefly, a very good experience.

Posted By C.J. in February, 2024

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Overall Rating -> 10

The website is easy to navigate and the images are incredible.

Posted By Lindsy in October, 2023

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Overall Rating -> 10

i love this site, the gems are always of good quality, i've been buy gifts from the site for 10 years, love it

Posted By Jf in January, 2024

Source: Bizrate

Overall Rating -> 9

Easy to use. Limited supply of higher quality gemstones.

Posted By Newfguy in February, 2024

Source: Bizrate

Gemstones A-Z

Buy Round Shape 12 mm Gems

0.57 ct Orange Sphalerite, 4.7 mm Round Cut From Spain

46.06 carat Ruby, loose Certified Ruby from Madagascar, Natural Gem, 28.9 x 28.8 mm

0.89 ct Oval Cut Peridot, 7.1 x 5.1 mm From China

1.56 carat Orange Hessonite Garnet, Oval loose Hessonite Garnet from Madagascar, Natural Untreated Gem, 8.7 x 7 mm

34.64 ct Oval Jasper, 30.1 x 22.1 mm From Indonesia

0.61 carat Oval Demantoid Garnet, loose Certified Demantoid Garnet from Namibia, Natural Untreated Gem, 5.8 x 4.1 mm

4.57 carat Carved Heart Amethyst, loose Certified Amethyst from Brazil, Natural Untreated Gem, 11.3 x 9.7 mm

2.83 ct Square Cut Rainbow Moonstone, 3.1 x 3.1 mm From India

3.46 carat Oval Amethyst, loose Certified Amethyst from Brazil, Natural Untreated Gem, 11 x 9 mm

1.33 ct Baguette Cut Color-Change Diaspore, 9.6 x 4.8 mm From Turkey

2.06 carat Orange Hessonite Garnet, Emerald Cut loose Hessonite Garnet from Sri Lanka, Natural Untreated Gem, 7.9 x 6 mm

8.35 carat Green Fluorite, Oval loose Fluorite from India, Natural Untreated Gem, 12.3 x 10.9 mm

0.81 ct Loose White Sapphire, 4.5 mm Diamond Cut From Madagascar

3.13 ct Multicolor Mystic Quartz, 11 x 8.9 mm Oval Concave Cut From Brazil

0.45 ct Loose White Sapphire, 4.4 mm Round Cut From Tanzania

4.48 carat Yellow Citrine, Round loose Citrine from Madagascar, Natural Untreated Gem, 11 mm

3.23 ct Round Checkerboard Smoky Quartz, 7.8 mm From Brazil

1.06 ct Purple Spinel, 7.3 x 4.8 mm Oval Cut From Tanzania

9.58 ct Marquise Ruby-Zoisite, 23.3 x 9.1 mm From Tanzania

22.36 ct Baguette Jasper, 20.9 x 15.5 mm From Indonesia

9.27 ct Loose Oval Lapis Lazuli, 15.1 x 11.4 mm From Afghanistan

0.8 ct Octagon Cut Color-Change Diaspore, 7.1 x 4.2 mm From Turkey

1.83 carat Pear Shape Amethyst, loose Certified Amethyst from Brazil, Natural Untreated Gem, 10.1 x 7.1 mm

2.38 carat Pink Tourmaline, Emerald Cut loose Tourmaline from Mozambique, Natural Untreated Gem, 9 x 6.1 mm

2.57 ct Red Andesine Labradorite, 10.2 x 8.2 mm Oval Cut From Congo

0.58 ct Loose Purple Sapphire, 7.8 x 4.6 mm Odd Shaped From Tanzania

0.97 carat Violet Sapphire, Pear Shape loose Sapphire from Sri Lanka, Natural Gem, 8.4 x 4.6 mm

1.23 carat Green Tourmaline, Oval loose Tourmaline from Mozambique, Natural Untreated Gem, 8.1 x 6 mm

2.28 carat Yellow Citrine, Oval loose Citrine from Brazil, Natural Untreated Gem, 9.7 x 7.9 mm

3.09 ct Square Cut Rainbow Moonstone, 3.1 x 3 mm From Sri Lanka

6.36 carat Yellow Citrine, Oval loose Citrine from Brazil, Natural Untreated Gem, 14 x 9.9 mm

1.66 ct Blue Kyanite, 8.2 x 6.2 mm Oval Cut From Nepal

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