Calibrated 18 x 13 mm Oval Shape Natural Loose Gemstones: GemSelect

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 oval shapes, facet cut and cabochon gems available now in 18 x13 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.

Read All

Gemstone Information

Over 19 Years in the Gemstone Business!

Thank you for trusting us with your purchase!

Overall Rating -> 9

My first purchase went well. I will purchase more gems in the future.

Posted By NoHalalAl in March, 2024

Source: Bizrate

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

Posted By Jf in January, 2024

Source: Bizrate

Overall Rating -> 10

The website is easy to search, the variety of gems is excellent and the educational information is interesting and helpful! Love browsing and shopping the GemSelect website!

Posted By Happiness in January, 2024

Source: Bizrate

Overall Rating -> 10

first time here sooooooooooo we will seeeee!!!!! so far so good!!!!!!

Posted By Seastone 56 in October, 2023

Source: Bizrate

Overall Rating -> 10

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

Posted By Erin in June, 2023

Source: Bizrate

Overall Rating -> 10

Perfect size I was looking for and great price

Posted By Izzy in September, 2023

Source: Bizrate

Overall Rating -> 9

So many gorgeous stones! The only "complaint" I have is it's difficult to visualize sizes in mm. Perhaps some way to compare in inches?It has been a long time since I bought stones from Gem select, but the process wasn't too difficult.

Posted By Ktreva52 in February, 2024

Source: Bizrate

Overall Rating -> 10

Everything fine.

Posted By Hilario in December, 2023

Source: Bizrate

Overall Rating -> 10

No issues at all. It was great.

Posted By LJXK in May, 2023

Source: Bizrate

Overall Rating -> 10

I had a great time searching all the lovely stones. This is my first precious loose stone purchase for my own work. I chose sapphire, and found some lovely briolettes. I wanted 3, but this set of 4 was perfect. Everything was quick and easy, and I'm excited.

Posted By Phoenix in February, 2024

Source: Bizrate

Overall Rating -> 10

Hello: You do have good website. Vast majority of folks would buy the Gems for its spiritual, physical / energy level, emotional level positive aspects. You have only very brief mention of this aspect of each Gem ..may be you can add little bit more about ways to leverage the beneificial effect of each gems i.e. some practical tips.ThanksRupen Patel

Posted By EarthDeep in February, 2024

Source: Bizrate

Overall Rating -> 10

I enjoyed browsing though different varieties of rubies. I felt that the experience was simple and easy to navigate!

Posted By Daws in July, 2023

Source: Bizrate

Overall Rating -> 10

Purchasing from Gem Select was a pleasant and easy experience. The photos of the stones I was interested in were an accurate depiction of the stones I received. Ordering was easy and the items arrived within a week. Over all it was a very positive experience.

Posted By Dee in September, 2023

Source: Bizrate

Overall Rating -> 7

I placed order#384714 based on the picture on your website and the stone came in much darker. I'm sure it's the same stone i ordered but your lighting made it seem a lighter blue. I was trying to match a stone for a customer and based on the picture it would have been close enough but the stone in person is a mile off.

Posted By Bobk in February, 2024

Source: Bizrate

Overall Rating -> 10

I really enjoy browsing through GemSelect. The selection is always marvelous and I love how detailed everything is described. The only thing I noticed is that when browsing through my phone, the videos of the gems do not load. If there were more videos of the gems, that would be amazing, though I understand that is a lot of work on GemSelect's part! Checking out is also very fast and easy, and I love that the return policy is very good, though I hope I don't have to use it anytime soon.

Posted By ChiChi in January, 2024

Source: Bizrate

Gemstones A-Z

Buy Oval Shape 18x13 mm Gems

2.61 carat Round Rhodolite Garnet, loose Certified Rhodolite Garnet from Tanzania, Natural Untreated Gems, 4.7 mm

0.77 carat Oval Peridot, loose Certified Peridot from China, Natural Untreated Gem, 6.9 x 5 mm

1.81 ct Blue Apatite, 5 x 3.9 mm Oval Cut From Madagascar

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

3.84 ct Red Andesine Labradorite, 11.1 x 9.1 mm Oval Cut From Congo

8.61 carat Swiss Blue Topaz, Marquise-Cut loose Topaz from Brazil, Natural Gems, 15.9 x 8 mm

0.68 ct Loose Pink Sapphire, 5.8 x 4 mm Oval Cut From Madagascar

1.35 ct Pink Morganite, 7.2 mm Round Cut From Afghanistan

4.75 carat Amethyst, loose Certified Amethyst from Brazil, Natural Untreated Gem, 11.3 x 11.2 mm

5.4 ct Asscher Cut Smoky Quartz, 10.5 x 10.4 mm From Brazil

3.12 carat Green Sapphire, Oval loose Sapphire from Tanzania, Natural Gems, 5.9 x 4.9 mm

20.68 ct Amethyst Geode Slice, 25.4 x 19.4 mm From Brazil

2.93 ct Loose Marquise Concave Cut Smoky Quartz, 17.8 x 7.1 mm From Brazil

2.47 carat Green Tourmaline, Emerald Cut loose Tourmaline from Mozambique, Natural Untreated Gem, 18.7 x 4 mm

0.55 ct Loose Yellow Sapphire, 4.8 mm Round Cut From Tanzania

1.35 ct Yellow Beryl, 7.1 mm Round Cut From Madagascar

1.97 carat Emerald Cut Amethyst, loose Certified Amethyst from Brazil, Natural Untreated Gem, 9.1 x 7 mm

1.78 carat Orange Hessonite Garnet, Oval loose Hessonite Garnet from Sri Lanka, Natural Untreated Gem, 7.9 x 6.7 mm

3.25 carat Blue Tanzanite, Oval loose Tanzanite from Tanzania, Natural Gems, 8.2 x 6.1 mm

0.77 carat Yellow Citrine, Trillion loose Citrine from Brazil, Natural Untreated Gem, 6.8 x 6.7 mm

1.15 ct Green Sphene, 6.9 x 5.2 mm Oval Cut From Sri Lanka

21.12 ct Green Jadeite, 23.8 x 17.4 mm Oval Cut From Myanmar

21.43 ct Oval Tiger's Eye Matrix, 24.9 x 17.2 mm From Mexico

2.51 carat Blue Tanzanite, Pear Shape loose Tanzanite from Tanzania, Natural Gems, 5 x 3 mm

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

2.41 ct Yellow Andesine Labradorite, 10.1 x 8.1 mm Oval Cut From Congo

1.92 ct Yellow Beryl, 8.2 mm Round Cut From Brazil

2.21 carat Sky Blue Topaz, Emerald Cut loose Topaz from Brazil, Natural Gems, 7 x 4.9 mm

113.4 ct Pyramid Cut Bloodstone, 31.1 x 30.5 mm From Madagascar

0.04 ct Black Diamond, 2 x 1.7 mm Princess Cut From India

6.9 ct Oval Tiger's Eye, 12.5 x 9.7 mm From Thailand

0.48 ct Loose Purple Sapphire, 4.8 mm Round Cut From Madagascar

Gemstone Information

Gemstone SHOP

POLICIES

WHO ARE WE?

Gemstone EDUCATION

WE ARE LOCATED AT