Marquise Shape 18 x 9 mm calibrated natural loose gems from GemSelect

Marquise Shape 18x9 mm Gems

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 18 mm x 9 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.

Gemstone Information

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Overall Rating -> 10

The site was easy to shop and the payment was secure. I’m looking forward to receiving my order!

Posted By JAB93 in June, 2023

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Overall Rating -> 8

1st time buy. The experience to date has been easy.

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Overall Rating -> 10

love yall

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Overall Rating -> 10

I’ve enjoyed purchasing stones from this site. It’s convenient and fairly priced.

Posted By Chico in May, 2023

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Overall Rating -> 10

Purchase process is easy. Make the selection online and pay for it. About a week to 10 days later the stone shows up. Very easy and on time.

Posted By Brien in October, 2022

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Overall Rating -> 10

You were the only site that had the color gems with oval cut in sizes 6mm to 4mm that I could find and it was very easy to find them with your search tool!

Posted By Streetdonuts in February, 2023

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Overall Rating -> 8

I like to use GemSelect for finding calibrated sizes of gemstones. I purchased sapphires a few years ago and found the quality to be outstanding so I went ahead and purchased some more today (different) and some really unique moonstone. I'm opening a jewelry busy soon and so accurate gemstone sizes, quality, and reliability as a supplier is really important to me. Gemselect seems to fill all those requirements.

Posted By J in November, 2022

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Overall Rating -> 8

Great selection, good prices and beautiful, simple user interface.

Posted By Swaggermuffinz in October, 2022

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Overall Rating -> 10

Gem select was a company we were just looking at their products and my wife liked her birthstone so we ordered it and when it came she was very happy with what she received and because of that she wants to order again to make earrings with the next order so Gem Select is the company we will be shopping from now on

Posted By Quasi in October, 2022

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Overall Rating -> 10

Gems look fantastic and just as advertised.

Posted By Jess in October, 2022

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Overall Rating -> 10

It was great i bet there is a way to just look for blue gemstones but I found em so it doesn't matter.

Posted By Aaron in October, 2022

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Overall Rating -> 10

Perfect size I was looking for and great price

Posted By Izzy in September, 2023

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Overall Rating -> 10

I have loved GemSelect for years; and have ordered many pretty and special gems for my personal use and for handmade gifts. Now I am going in a new direction and plan to design and build some lovelies for sale on the web.

Posted By A Stone's Throw in February, 2023

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Overall Rating -> 10

Love all the filters. Easy to find the size I needed.

Posted By Melinda in December, 2022

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Overall Rating -> 10

I recently bought some stones for Christmas gifts for my family from GemSelect and was thrilled at the speed they arrived to me. The descriptions were accurate and could be verified by myself upon receiving the stones, though the only issue i had was finding exact stones i wanted. The sorting system is fanastically detailed, but often seems to trim more results than expected when i was selecting things to look by. They arrived safely and all together, as described per my purchase order and i could not be more satisfied. There aren't many that are looking to buy loose stones like this, but it really gets the job done.

Posted By Lev in December, 2022

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Selected Gemstones

Gemstones A-Z

Buy Marquise Shape 18x9 mm Gems

7.69 ct Green Amazonite, 18.3 x 9.3 mm Marquise Cut From Madagascar

6.89 ct Green Amazonite, 17.8 x 9.1 mm Marquise Cut From Madagascar

5.35 ct Marquise Cut Amethyst, 17.8 x 9 mm From Brazil

5.85 ct Marquise Cut Amethyst, 18 x 9.2 mm From Brazil

7.56 ct Marquise Cut Amethyst, 18.2 x 9.3 mm From Brazil

5.79 ct Marquise Cut Amethyst, 17.8 x 8.8 mm From Brazil

5.15 ct Marquise Cut Amethyst, 17.6 x 9 mm From Brazil

14.56 ct Green Amazonite, 18.3 x 9.2 mm Marquise Cut From Madagascar

6.4 ct Marquise Cut Amethyst, 18.1 x 9.2 mm From Brazil

7.1 ct Green Amazonite, 18 x 9.3 mm Marquise Cut From Madagascar

7.9 ct Green Amazonite, 18 x 9.1 mm Marquise Cut From Madagascar

5.82 ct Green Amazonite, 18.2 x 9.3 mm Marquise Cut From Madagascar

6.22 ct Marquise Cut Amethyst, 18.1 x 9 mm From Brazil

14.58 ct Green Amazonite, 17.6 x 9.3 mm Marquise Cut From Madagascar

6.39 ct Green Amazonite, 17.8 x 9.1 mm Marquise Cut From Madagascar

6.27 ct Marquise Cut Amethyst, 18.1 x 9.3 mm From Brazil

8.12 ct Green Amazonite, 18.3 x 9.3 mm Marquise Cut From Madagascar

7.17 ct Green Amazonite, 17.9 x 9.1 mm Marquise Cut From Madagascar

6.53 ct Marquise Cut Amethyst, 18.1 x 9 mm From Brazil

5.15 ct Marquise Cut Amethyst, 17.6 x 9 mm From Brazil

5.48 ct Marquise Cut Amethyst, 17.6 x 8.8 mm From Brazil

6.9 ct Gray Jadeite, 17.5 x 9.3 mm Marquise Cut From Myanmar

6.84 ct Green Amazonite, 18.3 x 9.2 mm Marquise Cut From Madagascar

5.79 ct Gray Jadeite, 17.9 x 9 mm Marquise Cut From Myanmar

6.13 ct Marquise Cut Amethyst, 17.6 x 9.1 mm From Brazil

7.65 ct Green Amazonite, 18.1 x 9.3 mm Marquise Cut From Madagascar

6.44 ct Marquise Cut Amethyst, 17.8 x 9.3 mm From Brazil

6.66 ct Marquise Cut Amethyst, 18.2 x 9.2 mm From Brazil

6.1 ct Green Amazonite, 17.6 x 9.1 mm Marquise Cut From Madagascar

8 ct Green Amazonite, 18.4 x 9.3 mm Marquise Cut From Madagascar

4.49 ct Marquise Cut Amethyst, 17.3 x 9 mm From Brazil

4.9 ct Gray Jadeite, 18.7 x 8.8 mm Marquise Cut From Myanmar

Marquise Shape 18x9 mm Gems

Gemstone Information