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.

Read All

Gemstone Information

Over 19 Years in the Gemstone Business!

Thank you for trusting us with your purchase!

Overall Rating -> 10

Very good, very fast, everything as described.

Posted By B in October, 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

Awesome

Posted By Mic in May, 2023

Source: Bizrate

Overall Rating -> 10

I am excited for my first order, search tools were a great help to find the sapphire I needed for my next project! Thank you

Posted By Sue in April, 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 -> 9

I was in the market for birthstones for a lil gift project im doing. I'm no expert in gems or what not but the quality as far as i can tell seems to be spot on.

Posted By PixelComposer in January, 2024

Source: Bizrate

Overall Rating -> 9

GemSelect has a fantastic assortment of Semi-precious stones. I have not found any other web site with the variety you have.

Posted By RobDill in August, 2023

Source: Bizrate

Overall Rating -> 10

Everything was fine.

Posted By Matt in March, 2024

Source: Bizrate

Overall Rating -> 10

Great Job today! No issues!

Posted By Samlovesgems777 in August, 2023

Source: Bizrate

Overall Rating -> 9

I am of the opinion that the company gem select cares about the product beautiful gems it sells and the cost of the gem I purchased was small i was treated as if it cost a lot of money and product was described in detail and i felt good about the little stones i had ordered.

Posted By Sparkle in March, 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

Great website and information

Posted By Moonshot in December, 2023

Source: Bizrate

Overall Rating -> 8

I am currently pleased. I like the layout of the website.

Posted By RayPoppa in January, 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

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

Gemstones A-Z

Buy Round Shape 12 mm Gems

3.24 carat Yellow Citrine, Emerald Cut loose Citrine from Brazil, Natural Untreated Gems, 8 x 6.2 mm

4.91 carat Pear Shape Amethyst, loose Certified Amethyst from Brazil, Natural Untreated Gem, 14 x 9.9 mm

3 ct Marquise Rutile Quartz, 13.7 x 7.1 mm From India

43.18 carat Pear Tiger's Eye Matrix, loose Certified Tiger's Eye Matrix from Mexico, Natural Untreated Gem, 28.6 x 24.8 mm

1.85 carat Marquise Cut Amethyst, loose Certified Amethyst from Brazil, Natural Untreated Gem, 11.8 x 6 mm

12.33 carat Oval Tiger's Eye, loose Certified Tiger's Eye from Thailand, Natural Untreated Gem, 23 x 14.7 mm

0.73 ct Loose Pink Sapphire, 6 x 4.2 mm Oval Cut From Tanzania

0.43 carat Oval Amethyst, loose Certified Amethyst from Brazil, Natural Untreated Gem, 6 x 4.2 mm

0.6 ct Cushion Cut Color-Change Diaspore, 4.9 x 4.7 mm From Turkey

1.83 carat Oval Opal, loose Certified Opal from Ethiopia, Natural Untreated Gem, 11.8 x 7.9 mm

1.38 ct Loose Yellow Sapphire, 5 mm Round Cut From Tanzania

3.79 carat Yellow Citrine, Emerald Cut loose Citrine from Brazil, Natural Untreated Gem, 12 x 8.1 mm

0.42 ct Loose Pink Sapphire, 5.5 x 4.5 mm Oval Cut From Madagascar

2.65 carat Swiss Blue Topaz, Fancy-Cut loose Topaz from Brazil, Natural Gems, 10.1 x 5.1 mm

1.87 ct Loose Trillion Concave Cut Mystic Quartz, 8.1 x 8.1 mm From Brazil

2.02 ct Oval Sillimanite Cat's Eye, 7.6 x 5.3 mm From Madagascar

3.58 carat Pink Morganite, Pear loose Morganite from Afghanistan, Natural Untreated Gem, 13.9 x 8.1 mm

0.5 ct Loose Yellow Sapphire, 4.7 x 4.6 mm Heart Cut From Tanzania

0.31 carat Oval Emerald, loose Certified Emerald from Colombia, Natural Gem, 5.3 x 3.4 mm

4.05 carat Oval Amethyst, loose Certified Amethyst from Brazil, Natural Untreated Gems, 6.1 x 4.1 mm

8.3 ct Yellow Apatite, 11.1 x 11 mm Asscher Cut From Madagascar

5.87 ct Blue Green Turquoise, 19.6 x 13.3 mm Oval Cut From China

0.87 ct Loose Baguette Cut Smoky Quartz, 6.6 x 5.5 mm From Brazil

3.76 ct Oval Cut Andalusite, 6.2 x 4.1 mm From Brazil

0.7 ct Square Cut Color-Change Diaspore, 5.3 x 5.2 mm From Turkey

7.61 ct Round Quartz Cat's Eye, 12.2 mm From India

1.81 carat Yellow Citrine, Heart Checkerboard loose Citrine from Brazil, Natural Untreated Gem, 8.2 x 8 mm

13.63 carat Black Tourmaline, Emerald Cut loose Tourmaline from Tanzania, Natural Untreated Gem, 20.2 x 9.7 mm

7.89 carat Blue Green Fluorite, Pear Shape loose Fluorite from India, Natural Untreated Gem, 13.4 x 11.7 mm

0.27 ct Yellow Sphalerite, 3.9 x 3.3 mm Oval Cut From Spain

23.2 ct Oval Jasper, 29 x 20.4 mm From Indonesia

0.41 ct Yellow Sphalerite, 4.8 x 4 mm Oval Cut From Spain

Gemstone Information

Gemstone SHOP

POLICIES

WHO ARE WE?

Gemstone EDUCATION

WE ARE LOCATED AT