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 -> 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 !!

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

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Selection and purchasing online was very easy

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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

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Overall Rating -> 9

It went well

Posted By Rob in December, 2023

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Overall Rating -> 10

Everthing about researching and ordering from Gemselect was easy and uncomplicated. In the past I had payment problems, but your customer rep, Thomas, helped me get everything right. I will continue using Gemselet in the future for these reasons.

Posted By WildwillyfromArizona in August, 2023

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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 !

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Overall Rating -> 10

Great website and information

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The site is very easy to use and I will continue to shop here. The quality is superb

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Overall Rating -> 10

Great selection, I love your site! Great product visibility, information, etc.

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The website is easy to search, the variety of gems is excellent and the educational information is interesting and helpful! Love browsing and shopping the GemSelect website!

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Posted By RayPoppa in January, 2024

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Overall Rating -> 10

Hello: You do have good website. Vast majority of folks would buy the Gems for its spiritual, physical / energy level, emotional level positive aspects. You have only very brief mention of this aspect of each Gem ..may be you can add little bit more about ways to leverage the beneificial effect of each gems i.e. some practical tips.ThanksRupen Patel

Posted By EarthDeep in February, 2024

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Gemstones A-Z

Buy Marquise Shape 12x6 mm Gems

0.59 carat Green Sapphire, Cushion loose Sapphire from Madagascar, Natural Gem, 4.3 x 4.3 mm

1.24 carat Orange Hessonite Garnet, Oval loose Hessonite Garnet from Madagascar, Natural Untreated Gem, 7.3 x 5.8 mm

0.53 ct Loose Purple Sapphire, 5.5 x 4.4 mm Oval Cut From Tanzania

1.88 carat Emerald Cut Amethyst, loose Certified Amethyst from Brazil, Natural Untreated Gem, 9.1 x 6.9 mm

0.16 ct White Diamond, 2.7 mm Diamond Cut From India

4.68 ct Green Apatite, 9.1 x 8.9 mm Asscher Cut From Madagascar

2.71 ct Loose Yellow Sapphire, 4.8 mm Round Cut From Tanzania

0.12 ct Square Cut Iolite, 3 x 2.9 mm From Madagascar

0.53 carat Blue Sapphire, Trillion-Cut loose Sapphire from Madagascar, Natural Gem, 4.5 x 4.4 mm

3.88 carat Yellow Citrine, Briolette loose Citrine from Brazil, Natural Untreated Gem, 13.7 mm

1.36 ct Purple Spinel, 8.4 x 6.1 mm Oval Cut From Tanzania

0.2 carat Round Ruby, loose Certified Ruby from Myanmar, Natural Gem, 3.4 mm

0.38 ct Blue Apatite, 3.4 mm Round Cut From Madagascar

4.51 ct Trillion Pietersite, 14.4 x 12.7 mm From Namibia

30.15 carat Blue Aquamarine, Pear Shape loose Aquamarine from Madagascar, Natural Untreated Gem, 27.9 x 17.5 mm

33.76 ct Oval Jasper, 31.1 x 21.3 mm From Indonesia

0.6 ct Loose Pink Sapphire, 5.1 mm Round Cut From Madagascar

31.48 ct Oval Cat's Eye Opal, 27.1 x 18.7 mm From Madagascar

1.25 carat Yellow Citrine, Emerald Cut loose Citrine from Brazil, Natural Untreated Gem, 8 x 5.9 mm

3.2 carat Sky Blue Topaz, Oval loose Topaz from Brazil, Natural Gem, 10 x 8 mm

13.84 carat Pear Howlite, loose Certified Howlite from the United States, Natural Untreated Gem, 26 x 14.6 mm

70.41 ct Marquise Hematite, 29.4 x 13.6 mm From Brazil

5.05 ct Round Cut Smoky Quartz, 11.4 mm From Brazil

3.65 ct Oval Buff Top Chalcedony, 11.1 x 9.1 mm From Brazil

4.58 carat White Topaz, Cushion loose Topaz from Brazil, Natural Untreated Gems, 4.6 x 4.5 mm

3.53 ct Round Cut Peridot, 5.7 mm From China

3.11 carat Trillion Amethyst, loose Certified Amethyst from Brazil, Natural Untreated Gem, 10.1 x 10 mm

9.44 carat Yellow Citrine, Oval loose Citrine from Brazil, Natural Untreated Gems, 12.2 x 10 mm

4.03 carat Pear Prehnite, loose Certified Prehnite from South Africa, Natural Untreated Gem, 10.2 x 8.2 mm

3.7 ct Red Andesine Labradorite, 11.2 x 9.2 mm Oval Cut From Congo

1.13 carat Oval Opal, loose Certified Opal from Ethiopia, Natural Untreated Gem, 9.1 x 7 mm

6 ct Oval Prehnite, 8.6 x 6.7 mm From South Africa

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