X
Gemstone Search

Your Details

Please fill in your email address

Please fill in a password

Forgot your password?

Buy Trillion Shape 12x12 mm Gems

Trillion Shape 12x12 mm Gems Weight
Trillion Shape 12x12 mm Gems Size
Trillion Shape 12x12 mm Gems Clarity
Trillion Shape 12x12 mm Gems Price

Size Explained

Choose Size or Size Range
For Example: 6-7
For Example: 8-9
Bi-color
Black
Blue
Brown
Golden Trillion Shape 12x12 mm Gems
Gray
Green
Multicolor Trillion Shape 12x12 mm Gems
Orange
Pink Trillion Shape 12x12 mm Gems
Purple
Red
Turquoise
Violet
White
Yellow Trillion Shape 12x12 mm Gems
Single
Pairs
Lots
Faceted
Cabochons
Clear All
  • Actual Product Photos
  • Reliable Quality
  • Full Transparency
  • Large Selection
  • Affordable Prices
  • Fast, Secure Global Shipping
ID: 500195
Weight: 5.97ct
Size: 12 x 12 mm (calibrated)
Clarity: Transparent
Content: 1 pc
Price: $ 23.64
Item in Stock
More Options & Item Details
Add to Cart
ID: 645893
Weight: 4.47ct
Size: 12 x 12 mm (calibrated)
Clarity: Opaque
Content: 1 pc
Price: $ 13.94
Item in Stock
More Options & Item Details
Add to Cart
ID: 606565
Weight: 5.63ct
Size: 12 x 12 mm (calibrated)
Clarity: Transparent
Content: 1 pc
Price: $ 74.32
Item in Stock
More Options & Item Details
Add to Cart
ID: 606570
Weight: 5.33ct
Size: 12 x 12 mm (calibrated)
Clarity: Transparent
Content: 1 pc
Price: $ 70.36
Item in Stock
More Options & Item Details
Add to Cart
ID: 604861
Weight: 5.84ct
Size: 12 x 12 mm (calibrated)
Clarity: VVS-VS
Content: 1 pc
Price: $ 27.14
Item in Stock
More Options & Item Details
Add to Cart
ID: 605615
Weight: 5.99ct
Size: 12 x 12 mm (calibrated)
Clarity: Transparent
Content: 1 pc
Price: $ 79.07
Item in Stock
More Options & Item Details
Add to Cart
ID: 606580
Weight: 4.96ct
Size: 12 x 12 mm (calibrated)
Clarity: Transparent
Content: 1 pc
Price: $ 65.47
Item in Stock
More Options & Item Details
Add to Cart
ID: 599402
Weight: 7.74ct (total)
Size: 12 x 12 mm (calibrated)
Clarity: VVS-VS
Content: 2 pcs
Price: $ 37.09
Item in Stock
More Options & Item Details
Add to Cart
ID: 599401
Weight: 7.59ct (total)
Size: 12 x 12 mm (calibrated)
Clarity: VVS-VS
Content: 2 pcs
Price: $ 36.37
Item in Stock
More Options & Item Details
Add to Cart
ID: 498560
Weight: 4.72ct
Size: 12 x 12 mm (calibrated)
Clarity: VVS
Content: 1 pc
Price: $ 43.61
Item in Stock
More Options & Item Details
Add to Cart
ID: 605610
Weight: 4.86ct
Size: 12 x 12 mm (calibrated)
Clarity: Transparent
Content: 1 pc
Price: $ 64.15
Item in Stock
More Options & Item Details
Add to Cart

GemSelect Certified Store Reviews

GemSelect: Over 22 Years in the Gemstone Business! Thank you for trusting us with your purchase!

Overall Rating -> 10 star ratings

I trust this company to deliver exactly what is offered. I have never had to return a selection of Gems. I appreciate the company's detailed description of their product. It helps this customer find mounts before the gems arrive. Any day of the year one can find a wide selection of gems, be it by price, color, cut, lot or single. Pricing does not jump all over the place and stays reasonable. Be assured your items will arrive in perfect condition as the company's shipping department does a great job.

Posted By Miss Sherrie in August, 2024
Source: Bizrate

Overall Rating -> 10 star ratings

Excellent selection and easy to use, well done site

Posted By Steph in December, 2024
Source: Bizrate

Overall Rating -> 10 star ratings

I love the gems and your website, every time I want to buy I usually spend between 6 and 8 hours on your website.

Posted By Bryan De David in April, 2025
Source: Bizrate

Overall Rating -> 10 star ratings

Easy to conduct search, good amount of stock to select from along with variety of prices.

Posted By Que in June, 2025
Source: Bizrate

Overall Rating -> 10 star ratings

Very surprised how quick and efficient it was to checkout and pay. Also found exactly what I was looking for no issues.

Posted By Watson in May, 2025
Source: Bizrate

Overall Rating -> 10 star ratings

I love browsing the site and everything is easy to find. There is just so much I get lost for hours. Sometimes I wish there were videos of some gems, but other than that I love shopping with GemSelect and I have referred the site to many people many times. I work in the jewelry industry myself and I love to show off what Ive had made with my gems from GemSelect! Thank you

Posted By Antennaesglow in July, 2024
Source: Bizrate

Overall Rating -> 9 star ratings

I did not have any problems

Posted By Clilrichard in January, 2025
Source: Bizrate

Overall Rating -> 10 star ratings

I always enjoy the selection and the unique cuts I can find here. I would love to see more hex cuts tho! Maybe some rose cuts too!

Posted By Blkfower83 in October, 2024
Source: Bizrate

Overall Rating -> 10 star ratings

I am never let down by GemSelect. I love that you get the exact stone you want. Shipping is always in a few days. I have spread the word about GemSelect on social media jewelry creating groups that I attend. This sapphire is going to make one gorgeous ring

Posted By Desertchick in April, 2025
Source: Bizrate

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 Trillion shapes, facet cut and cabochon gems available now in 12 mm 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 meant nor 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 around 0.3 mm or slightly higher even. This small variance can usually be accommodated for 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

Over 19 Years in the Gemstone Business!

Thank you for trusting us with your purchase!

Overall Rating -> 10 star ratings

I trust this company to deliver exactly what is offered. I have never had to return a selection of Gems. I appreciate the company's detailed description of their product. It helps this customer find mounts before the gems arrive. Any day of the year one can find a wide selection of gems, be it by price, color, cut, lot or single. Pricing does not jump all over the place and stays reasonable. Be assured your items will arrive in perfect condition as the company's shipping department does a great job.

Posted By Miss Sherrie in August, 2024
Source: Bizrate

Overall Rating -> 10 star ratings

Excellent selection and easy to use, well done site

Posted By Steph in December, 2024
Source: Bizrate

Overall Rating -> 10 star ratings

I love the gems and your website, every time I want to buy I usually spend between 6 and 8 hours on your website.

Posted By Bryan De David in April, 2025
Source: Bizrate

Overall Rating -> 10 star ratings

Easy to conduct search, good amount of stock to select from along with variety of prices.

Posted By Que in June, 2025
Source: Bizrate

Overall Rating -> 10 star ratings

Very surprised how quick and efficient it was to checkout and pay. Also found exactly what I was looking for no issues.

Posted By Watson in May, 2025
Source: Bizrate

Overall Rating -> 10 star ratings

I love browsing the site and everything is easy to find. There is just so much I get lost for hours. Sometimes I wish there were videos of some gems, but other than that I love shopping with GemSelect and I have referred the site to many people many times. I work in the jewelry industry myself and I love to show off what Ive had made with my gems from GemSelect! Thank you

Posted By Antennaesglow in July, 2024
Source: Bizrate

Overall Rating -> 9 star ratings

I did not have any problems

Posted By Clilrichard in January, 2025
Source: Bizrate

Overall Rating -> 10 star ratings

I always enjoy the selection and the unique cuts I can find here. I would love to see more hex cuts tho! Maybe some rose cuts too!

Posted By Blkfower83 in October, 2024
Source: Bizrate

Overall Rating -> 10 star ratings

I am never let down by GemSelect. I love that you get the exact stone you want. Shipping is always in a few days. I have spread the word about GemSelect on social media jewelry creating groups that I attend. This sapphire is going to make one gorgeous ring

Posted By Desertchick in April, 2025
Source: Bizrate
Enlarged Gemstone Image