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, the whole process was just great.

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The gems were as described, which is kind of rare these days. I am happy with the purchase, and delevery on time.

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It was easy to navigate and I hope that the gem is as nice as the picture

Posted By 1 in April, 2024

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Easy to find the stones I was looking for. Always good quality stones

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I was looking for a source for affordable genuine gemstones for my grandson who is currently very interested in rocks and gems. I was quite surprised and pleased to find GemSelect and finding the right stones at the right price couldn't have been simpler.

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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

Best place to buy gem stones, dont bother shopping else where. Prices are great, no issues with shipping and customer service is the best.

Posted By J in December, 2023

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Overall Rating -> 10

blessed be the lord blessed be the saved blessed be the work blessed be the traveled i write down my good times in these stones and when times are gray i can still se the sunny days refract in these stones

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Overall Rating -> 10

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

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Good interaction with site

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Overall Rating -> 9

Easy to use. Limited supply of higher quality gemstones.

Posted By Newfguy in February, 2024

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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.

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Overall Rating -> 10

I have used GemSelect for several years and plan to shop more in the further. This is a good source of information on gemstones. I love looking at and learning about them. Lot more than I ever knew existed.

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Overall Rating -> 10

I love your selection of gems. My only complaing is I wish I could put in a page number to return to that page.When there are over 60 pages of gems it is hard to return to a page with a gem I am considering.

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Gemstones A-Z

Buy Marquise Shape 12x6 mm Gems

3.06 ct Round Strawberry Quartz, 8.2 mm From Brazil

3.47 carat Swiss Blue Topaz, Marquise-Cut loose Topaz from Brazil, Natural Gem, 14.9 x 6.9 mm

44.65 ct Brown Moonstone, 25.3 x 18.1 mm Oval Cut From India

11.73 ct Round Boulder Opal, 19.1 mm From Australia

0.59 carat London Blue Topaz, Square loose Topaz from Brazil, Natural Gem, 4.9 x 4.9 mm

0.58 ct Round Labradorite, 5.1 mm From Madagascar

0.9 carat Yellow Citrine, Marquise Cut loose Citrine from Brazil, Natural Untreated Gem, 9.1 x 5.1 mm

1.95 ct Pink Morganite, 8.1 mm Round Cut From Afghanistan

3.84 carat Oval Amethyst, loose Certified Amethyst from Brazil, Natural Untreated Gems, 6 x 4.1 mm

1.08 ct Loose Orange Sapphire, 6 x 4.1 mm Oval Cut From Tanzania

10.05 ct Yellow Quartz, 16 x 11.9 mm Carved From Brazil

5.88 ct Oval Coral, 15.6 x 11.5 mm From Indonesia

0.7 ct Cushion Cut Color-Change Diaspore, 5.2 x 5.1 mm From Turkey

8.06 ct Oval Quartz Cat's Eye, 12.6 x 10.2 mm From Sri Lanka

1.7 ct Pink Kunzite, 6.8 x 6.4 mm Octagon Cut From Afghanistan

6.64 ct Trillion Fire Agate, 16.9 x 11.6 mm From Mexico

4.8 carat Round Amethyst, loose Certified Amethyst from Brazil, Natural Untreated Gem, 11.1 mm

1.74 ct Oval Cut Strawberry Quartz, 9 x 6.9 mm From Russia

8.75 ct Green Agate, 13.6 x 11.8 mm Oval Cut From India

7.6 ct Green Agate, 12.8 x 12.4 mm Oval Cut From India

1.65 carat Blue Green Fluorite, Pear Shape loose Fluorite from India, Natural Untreated Gem, 8.5 x 6.3 mm

0.64 carat Yellow Citrine, Heart loose Citrine from Brazil, Natural Untreated Gem, 6 x 5.9 mm

1.45 ct Loose Orange Moonstone, 10.1 x 5 mm Marquise Cut From India

1.02 ct Blue Kyanite, 7 x 4.9 mm Oval Cut From Nepal

21.4 carat Multicolor Ammolite, loose Ammolite from Canada, Natural Gem, 26.7 x 19.4 mm

2.15 carat Orange Hessonite Garnet, Oval loose Hessonite Garnet from Madagascar, Natural Untreated Gem, 8.8 x 7.2 mm

82.38 carat Swiss Blue Topaz, Oval Concave Cut loose Topaz from Brazil, Natural Gem, 31.7 x 23.6 mm

5.87 ct Pink Morganite, 13.9 x 10 mm Oval Cut From Afghanistan

0.15 ct White Diamond, 2.7 mm Diamond Cut From India

0.39 ct Purple Spinel, 4.7 x 3.7 mm Cushion Cut From Tanzania

6.75 ct Oval Actinolite Cat's Eye, 13.5 x 11.6 mm From the United States

31.94 ct Oval Tiger's Eye Matrix, 31.1 x 19.9 mm From Mexico

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