Calibrated Size for Octagon Cut Gemstones 16x12 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 Octagon shape / Emerald-Cut, faceted and cabochon gems available now in 16 x 12 mm size range. Shop a wide range of calibrated gemstones by size online at wholesale from GemSelect.

As a general guideline, when it comes to 'calibrated' gems, they are not usually expected to be cut to exact measurements. 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

Perfect size I was looking for and great price

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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

The website is easy to navigate and has a great selection. I am an amateur silver smith casting jewelry with stones

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Great website and information

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Overall Rating -> 10

After having looked at other purchasing sites, this is my first choice.

Posted By MJC in January, 2024

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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 -> 9

I was in the market for birthstones for a lil gift project im doing. I'm no expert in gems or what not but the quality as far as i can tell seems to be spot on.

Posted By PixelComposer in January, 2024

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Overall Rating -> 10

Had a problem ordering first time. Someone from Gem Select reached out to me and cleared problem and I made purchase.

Posted By Myrtle in February, 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 -> 9

Never bought anything on this website before, but it probably won't be my last purchase. Definitely one of the easiest to use and most informative sites I've ever been to.

Posted By Bob in November, 2023

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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.

Posted By Iggywiggly in January, 2024

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Overall Rating -> 10

Todo muy bien en la compra ahora esperar recibir el pedido.

Posted By MAGSMX in August, 2023

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Overall Rating -> 10

Great selection

Posted By GHS40 in December, 2023

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Overall Rating -> 10

i love this site, the gems are always of good quality, i've been buy gifts from the site for 10 years, love it

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Gemstones A-Z

Buy Octagon Shape 16x12 mm Gems

4.32 ct Round Strawberry Quartz, 8.8 mm From Russia

1.16 carat Yellow Citrine, Trillion loose Citrine from Brazil, Natural Untreated Gem, 7.1 x 7.1 mm

30.68 ct Oval Jasper, 31.1 x 21.7 mm From Indonesia

34.99 carat Pear Tiger's Eye Matrix, loose Certified Tiger's Eye Matrix from Mexico, Natural Untreated Gem, 29.9 x 22.7 mm

26.24 ct Oval Obsidian, 28.5 x 18.2 mm From the United States

9.51 ct Yellow Quartz, 19.2 x 12.9 mm Marquise Concave Cut From Brazil

1.61 carat Sky Blue Topaz, Pear Shape loose Topaz from Brazil, Natural Gems, 6.9 x 5 mm

5.61 carat Blue Green Fluorite, Marquise Cut loose Fluorite from India, Natural Untreated Gem, 14.9 x 8 mm

0.96 carat Orange Hessonite Garnet, Oval loose Hessonite Garnet from Madagascar, Natural Untreated Gem, 6.9 x 5.2 mm

11 ct Trillion Pietersite, 20.8 x 19.7 mm From Namibia

6.11 ct Pink Kunzite, 11 x 9.5 mm Oval Cut From Afghanistan

0.51 ct Loose Yellow Sapphire, 3.3 x 3.3 mm Princess Cut From Tanzania

3.51 ct Loose Oval Malachite, 10 x 7.2 mm From Congo

1.38 ct Oval Cat's Eye Moonstone, 8 x 6 mm From India

3.37 ct Orange Sunstone, 8 mm Round Cut From India

1.66 ct Orange Sunstone, 9.5 x 7.2 mm Oval Cut From India

2.17 carat Swiss Blue Topaz, Pear Shape loose Topaz from Brazil, Natural Gems, 6.8 x 4.9 mm

23.86 carat Pear Tiger's Eye Matrix, loose Certified Tiger's Eye Matrix from Mexico, Natural Untreated Gem, 21.8 x 21.3 mm

1.55 carat Yellow Citrine, Emerald Cut loose Citrine from Brazil, Natural Untreated Gem, 8.2 x 6.3 mm

2.32 carat Blue Green Fluorite, Pear Shape loose Fluorite from India, Natural Untreated Gem, 9 x 6.4 mm

12.73 ct Oval Rainbow Moonstone, 19.9 x 11.1 mm From the United States

0.2 ct Square Cut Iolite, 2.7 x 2.5 mm From Madagascar

5.88 ct White Moonstone, 9.2 mm Round Cut From India

1.77 carat Yellow Citrine, Oval loose Citrine from Brazil, Natural Untreated Gem, 8.8 x 6.9 mm

67.56 ct Green Agate, 29.4 x 24.5 mm Oval Cut From India

7.81 ct Pink Morganite, 13.9 x 10.1 mm Oval Cut From Afghanistan

32.4 ct Cushion Jasper, 31.3 x 19.5 mm From Indonesia

0.69 ct Loose Orange Sapphire, 5.9 x 4 mm Oval Cut From Tanzania

7.01 ct Black Spinel, 9.1 mm Round Rose Cut From Thailand

23.03 carat Pear Rutile Quartz, loose Certified Rutile Quartz from India, Natural Untreated Gem, 23.7 x 16.4 mm

3.32 carat Sky Blue Topaz, Pear Shape loose Topaz from Brazil, Natural Gems, 7.2 x 5.2 mm

3.55 carat Heart Pyrope Garnet, loose Certified Pyrope Garnet from Mozambique, Natural Untreated Gems, 8 x 7.8 mm

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