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

it was good

Posted By Bobk in January, 2024

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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 !

Posted By Jen in August, 2023

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Overall Rating -> 10

Awesome

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Overall Rating -> 10

Gem Select has gems at afffordable prices.

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Overall Rating -> 10

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Overall Rating -> 9

It went well

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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.

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Overall Rating -> 10

Very detailed and great pictures

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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 -> 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.

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Overall Rating -> 10

Selection ability was straightforward and easy.

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Overall Rating -> 10

The website was very easy to navigate. We appreciated the details about each gem, and the sort and search features of the website were helpful and easy to use.

Posted By AV in May, 2023

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Overall Rating -> 9

Not easy enough to buy by exact size, and many stones aren't carbechon curved shape on top

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Overall Rating -> 10

Found what I was looking for

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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

9.96 ct Marquise Labradorite, 22.2 x 10.8 mm From Madagascar

4.19 carat White Zircon, Round loose Zircon from Cambodia, Natural Gems, 6.8 mm

2.71 ct Oval Sillimanite Cat's Eye, 7.6 x 5.6 mm From Madagascar

1.34 ct Pink Morganite, 7.4 mm Round Cut From Afghanistan

49.99 ct Yellow Quartz, 23.3 x 19.7 mm Oval Portuguese Cut From Brazil

2.49 carat Pink Tourmaline, Emerald Cut loose Tourmaline from Tanzania, Natural Untreated Gem, 8.6 x 5.8 mm

3.02 ct Brown Diamond, 8.2 x 7.8 mm Cushion Cut From South Africa

1.22 carat Heart Pyrope Garnet, loose Certified Pyrope Garnet from Mozambique, Natural Untreated Gems, 5.1 x 5 mm

41.72 carat Pear Chrysocolla, loose Certified Chrysocolla from Australia, Natural Untreated Gem, 39 x 23.3 mm

2.8 carat Marquise Cut Pyrope Garnet, loose Certified Pyrope Garnet from Mozambique, Natural Untreated Gems, 10 x 5.1 mm

14.29 ct Yellow Quartz, 10.1 x 10.1 mm Carved From Brazil

0.47 ct Orange Sphalerite, 4.7 mm Round Cut From Spain

6.68 carat Oval Amethyst, loose Certified Amethyst from Brazil, Natural Untreated Gems, 10 x 7.9 mm

8.28 carat Swiss Blue Topaz, Marquise-Cut loose Topaz from Brazil, Natural Gems, 15.7 x 7.9 mm

1.23 carat Oval Opal, loose Certified Opal from Australia, Natural Untreated Gem, 8.9 x 6.8 mm

5.27 carat Orange Hessonite Garnet, Emerald Cut loose Hessonite Garnet from Sri Lanka, Natural Untreated Gems, 6.8 x 5 mm

21.17 ct Oval Chalcedony, 26.2 x 18.4 mm From Brazil

1.41 ct Oval Sillimanite Cat's Eye, 7.6 x 5.1 mm From Madagascar

1.22 carat Oval Emerald, loose Certified Emerald from Colombia, Natural Gem, 7.2 x 6 mm

0.6 ct Loose Yellow Sapphire, 6.1 x 4.1 mm Oval Cut From Tanzania

2.8 carat Round Tsavorite Garnet, loose Certified Tsavorite Garnet from Tanzania, Natural Untreated Gems, 2.4 mm

12.99 ct Pink Coral, 26.7 x 20.8 mm Carved From Taiwan

27.4 ct Yellow Quartz, 19.2 x 19.1 mm Cushion Checkerboard From Brazil

8.14 ct Oval Actinolite Cat's Eye, 15.5 x 11.9 mm From the United States

12.82 ct Round Cut Smoky Quartz, 16.5 mm From Brazil

0.62 carat Heart Pyrope Garnet, loose Certified Pyrope Garnet from the United States, Natural Untreated Gem, 5.3 x 5.2 mm

1.33 ct Oval Checkerboard Labradorite, 7.2 x 6.2 mm From Madagascar

10.66 ct Oval Actinolite Cat's Eye, 16.1 x 12.7 mm From the United States

7.17 carat White Zircon, Oval loose Zircon from Cambodia, Natural Gems, 6.1 x 4.2 mm

35.08 ct Oval Charoite, 27.6 x 18 mm From Russia

2.51 carat Orange Hessonite Garnet, Oval loose Hessonite Garnet from Madagascar, Natural Untreated Gem, 9.2 x 7.6 mm

69.57 ct Amethyst Geode Slice, 41.5 x 29.6 mm From Brazil

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