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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Gemstones A-Z

Buy Marquise Shape 12x6 mm Gems

0.77 ct Loose Violet Sapphire, 6.1 x 4.7 mm Oval Cut From Tanzania

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

16.28 ct Oval Rose Quartz, 18 x 15.1 mm From South Africa

4.26 carat Pink Malaya Garnet, Round loose Malaya Garnet from Tanzania, Natural Untreated Gems, 5.5 mm

5.71 carat Yellow Citrine, Oval loose Citrine from Brazil, Natural Untreated Gems, 10.9 x 8.9 mm

4.52 ct Yellow Quartz, 12.7 x 9.9 mm Carved From Brazil

1.77 ct Loose Round Cut Lapis Lazuli, 6.2 mm From Afghanistan

4.59 carat Yellow Citrine, Oval loose Citrine from Brazil, Natural Untreated Gem, 12.6 x 10.1 mm

2.63 carat White Zircon, Oval loose Zircon from Cambodia, Natural Gems, 7.1 x 5.1 mm

0.55 carat Orange Sapphire, Pear Shape loose Sapphire from Tanzania, Natural Gem, 6 x 4 mm

1.66 carat Green Tourmaline, Emerald Cut loose Tourmaline from Mozambique, Natural Untreated Gem, 18.5 x 3.1 mm

3.41 ct Round Spectrolite, 8.1 mm From Finland

5.97 carat Sky Blue Topaz, Emerald Cut loose Topaz from Cambodia, Natural Gems, 8.2 x 7.9 mm

38.23 ct Pencil Cut Strawberry Quartz, 39.4 x 11.6 mm From Russia

33.44 carat Oval Amethyst, loose Certified Amethyst from Brazil, Natural Untreated Gem, 21.7 x 18.1 mm

3000 ct Oval Malachite, 139.4 x 82.7 mm From Congo

2.65 carat Trillion Amethyst, loose Certified Amethyst from Brazil, Natural Untreated Gem, 10 x 9.9 mm

6.28 ct Baguette Tiger's Eye, 12 x 10 mm From Thailand

2.16 carat Sky Blue Topaz, Round loose Topaz from Brazil, Natural Gems, 6.2 mm

1.19 ct Loose Pink Tourmaline, 7.8 x 5.6 mm Oval Cabochon From Mozambique

24.69 ct Green Aventurine, 38.2 x 9.8 mm Pencil Cut From Brazil

2.21 carat Round Amethyst, loose Certified Amethyst from Brazil, Natural Untreated Gem, 8.9 mm

2.71 carat Green Tourmaline, Carved Leaf loose Tourmaline from Mozambique, Natural Untreated Gem, 13.3 x 10.5 mm

0.7 ct Loose Yellow Sapphire, 5.9 x 4 mm Oval Cut From Tanzania

15.29 ct Round Agate, 14.8 mm From Indonesia

2.94 carat Sky Blue Topaz, Pear Shape loose Topaz from Brazil, Natural Gems, 6.1 x 4.2 mm

89.75 carat Oval Amethyst, loose Certified Amethyst from Brazil, Natural Untreated Gem, 34.6 x 26.2 mm

40.19 ct Square Maw-Sit-Sit, 16.8 x 16.6 mm From Myanmar

0.79 ct Loose Gray Spinel, 5.3 x 4.6 mm Cushion Cut From Tanzania

12.69 ct Oval Pietersite, 18 x 13.3 mm From Namibia

2.61 carat Sky Blue Topaz, Marquise Cut loose Topaz from Brazil, Natural Gems, 10.2 x 5.2 mm

1.68 carat Blue Sapphire, Princess-Cut loose Sapphire from Sri Lanka, Natural Gems, 2 x 2 mm

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