Calibrated Marquise Cut Gemstones in Size 12x6 mm

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 marquise shaped facet cut gems, gemstone carvings and cabochons available in 12 mm x 6 mm sizes. For the largest selection of colored gemstones, Shop GemSelect Online.

As a general guideline, when it comes to calibrated gems, they are not usually expected to be cut to exact measurements and specifications. But rather, they're cut with slight variance in size, though the close approximatation in size is not clearly defined, there are general guidelines for what is considered acceptable. Obviously larger and heavy carat weight stones allow more room in size for variance, while smaller stones may leave little to none. This means a large 30mm calibrated gemstone, could actually be closer to 31 millimeters. For this reason, we recommend to always view the exact size in addition to the calibrated size details. The exact size will inform you of the variance you can expect. Some setting styles are more flexible with variance, such as prong settings, while other styles of mountings may need almost an exact size to the fraction of millimeter.

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 round shape settings will allow 0.3 mm or slightly higher even. This small variance can usually be accommodated for most 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 -> 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

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Overall Rating -> 10

I have actually done business with them before and was quite satisfied with them then.My Mother collected turtle items and when I saw the Mother of Pearl turtle...I just thought of her and decided to buy it. It's even tinier than I thought, but so adorable!The gemstones I bought are for jewelry for my daughter's birthday.

Posted By Ktreva52 in February, 2024

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Overall Rating -> 10

I found it to be easy to browse and easy to use

Posted By Kyle in December, 2023

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Overall Rating -> 7

I feel pretty good so far, pending the delivery of the item ordered.

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Overall Rating -> 10

great. thank you

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Overall Rating -> 10

Trustworthy site. I've had several good experiences with company. Products always have met my expectations. Thank you.

Posted By Ray in February, 2024

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Overall Rating -> 10

I bought a small ring green so I may practice my jewelry making.

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Overall Rating -> 9

making my own jewelry for my birth stone

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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

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Overall Rating -> 10

Very excited and impressed with all your products. Keep up the good work....more different stones to choose from. I like Cabachons.

Posted By Meow in June, 2023

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Overall Rating -> 10

I was pleased with the selection of gems, the ease of navigating, and the smooth checkout

Posted By JamesMichael781 in September, 2023

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Overall Rating -> 10

The website is very easy to use. The search function, filter and sort functions are very helpful.

Posted By Sboro in August, 2023

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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

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Overall Rating -> 9

Overall good, shipping prices just seem a little on the high side.

Posted By Steve in August, 2023

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Overall Rating -> 10

Excellent site.

Posted By Boru in December, 2023

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Gemstones A-Z

Buy Marquise Shape 12x6 mm Gems

45.79 carat Pear Jasper, loose Certified Jasper from Indonesia, Natural Untreated Gem, 34.6 x 27.7 mm

10.63 ct Yellow Apatite, 14.4 x 13.6 mm Heart Cut From Madagascar

2.07 carat Blue Zircon, Diamond-Cut loose Zircon from Cambodia, Natural Gems, 4.5 mm

0.04 ct Loose Blue Diamond, 2.1 mm Diamond Cut From India

5.46 ct Round Cut Smoky Quartz, 12.5 mm From Brazil

4.26 carat Pear Shape Amethyst, loose Certified Amethyst from Brazil, Natural Untreated Gem, 13.9 x 9.5 mm

0.46 carat Pink Sapphire, Pear Shape loose Sapphire from Tanzania, Natural Gem, 6.7 x 4.9 mm

2.59 ct Cushion Cut Peridot, 8.1 x 7.2 mm From Myanmar

6.94 carat Blue Green Apatite, Pear Shape loose Apatite from Madagascar, Natural Gem, 16.3 x 10.3 mm

7.23 carat Swiss Blue Topaz, Emerald-Cut loose Topaz from Brazil, Natural Gems, 8.1 x 6 mm

1.52 ct Yellow Beryl, 9.1 x 6.7 mm Oval Cut From Brazil

7.63 carat Swiss Blue Topaz, Marquise-Cut loose Topaz from Brazil, Natural Gems, 15.1 x 7.1 mm

0.23 ct Round Cut Kornerupine, 3.6 mm From Sri Lanka

4.39 carat Sky Blue Topaz, Round loose Topaz from Brazil, Natural Gems, 8.1 mm

0.92 ct Loose Purple Sapphire, 5.1 x 4.1 mm Oval Cut From Madagascar

19.63 ct Oval Tiger's Eye, 24.7 x 16.6 mm From Thailand

3.61 carat Oval Strawberry Quartz, loose Certified from India, Natural Untreated Gem, 12 x 10 mm

0.94 carat Emerald Cut Emerald, loose Certified Emerald from Colombia, Natural Gem, 6 x 5.6 mm

33.15 ct Loose Oval Malachite, 23.9 x 17.1 mm From Congo

0.61 carat Pear Shape Color-Change Diaspore, loose Certified Color-Change Diaspore from Turkey, Natural Untreated Gem, 8.1 x 3.7 mm

4.67 ct White Moonstone, 8.2 mm Round Cut From India

1.35 ct Oval Cut Peridot, 8 x 6 mm From China

1.73 ct Oval Cut Golden Beryl, 10 x 7.5 mm From Brazil

5.94 carat Carved Heart Amethyst, loose Certified Amethyst from Brazil, Natural Untreated Gem, 13.6 x 11.1 mm

1.99 carat Orange Hessonite Garnet, Square loose Hessonite Garnet from Sri Lanka, Natural Untreated Gems, 3.7 x 3.7 mm

4.86 carat Yellow Citrine, Oval loose Citrine from Brazil, Natural Untreated Gem, 14 x 9.8 mm

1.81 carat Orange Hessonite Garnet, Cushion loose Hessonite Garnet from Madagascar, Natural Untreated Gem, 8 x 6 mm

1.22 carat Pear Shape Black Opal, loose Certified Black Opal from Ethiopia, Natural Gem, 13 x 7.9 mm

1.06 carat Green Tourmaline, Emerald Cut loose Tourmaline from Mozambique, Natural Untreated Gem, 13.7 x 3.1 mm

1.36 carat Oval Ruby, loose Certified Ruby from Madagascar, Natural Gem, 7.7 x 5.8 mm

13.78 carat Pear Jasper, loose Certified Jasper from Indonesia, Natural Untreated Gems, 23.6 x 13.9 mm

1.8 carat Orange Hessonite Garnet, Oval loose Hessonite Garnet from Madagascar, Natural Untreated Gem, 8.3 x 6.7 mm

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