X
Gemstone Search
90,000+ Happy Customers
20+ Years In Business
Call Us Mon–Fri 8am–5pm

Your Details

Please fill in your email address

Please fill in a password

Forgot your password?

Buy 12 mm Round Calibrated Gemstones from GemSelect

Round Shape 12 mm Gems Weight
Round Shape 12 mm Gems Size
Round Shape 12 mm Gems Clarity
Round Shape 12 mm Gems Price

Size Explained

Choose Size or Size Range
For Example: 6-7
For Example: 8-9
Bi-color
Black Round Shape 12 mm Gems
Blue Round Shape 12 mm Gems
Brown Round Shape 12 mm Gems
Golden
Gray Round Shape 12 mm Gems
Green Round Shape 12 mm Gems
Multicolor Round Shape 12 mm Gems
Orange Round Shape 12 mm Gems
Pink Round Shape 12 mm Gems
Purple
Red Round Shape 12 mm Gems
Turquoise Round Shape 12 mm Gems
Violet Round Shape 12 mm Gems
White Round Shape 12 mm Gems
Yellow Round Shape 12 mm Gems
Single
Pairs
Lots
Faceted
Cabochons
Clear All

8.50ct Black Star Diopside, Round, Opaque

12 mm (calibrated)

$ 42.33

View Gem

5.80ct Brown Smoky Quartz, Round, VVS

12 mm (calibrated)

$ 19.07

View Gem

5.28ct Yellow Quartz, Round, VVS-VS

12 mm (calibrated)

$ 11.57

View Gem

5.14ct Brown Smoky Quartz, Round, Transparent

12 mm (calibrated)

$ 21.57

View Gem

22.63ctw Multicolor Jasper, Sphere / Ball, Opaque

12 mm (calibrated)

$ 24.79

View Gem

15.42ctw Multicolor Labradorite, Round, Translucent

12 mm (calibrated)

$ 27.65

View Gem

5.43ct Brown Smoky Quartz, Round, VVS

12 mm (calibrated)

$ 14.88

View Gem

4.23ct Brown Rutile Quartz, Round, Transparent

12 mm (calibrated)

$ 10.62

View Gem

7.55ct Multicolor Labradorite, Round, Translucent

12 mm (calibrated)

$ 18.34

View Gem

6.16ct Violet Amethyst, Round, VVS-VS

12 mm (calibrated)

$ 36.81

View Gem

15.39ctw Black Spinel, Round, Opaque

12 mm (calibrated)

$ 50.59

View Gem

7.63ct White Quartz Cat'S Eye, Round, Transparent

12 mm (calibrated)

$ 33.43

View Gem

10.02ctw Yellow Quartz, Round, VVS-VS

12 mm (calibrated)

$ 45.74

View Gem

6.89ct Blue Larimar, Round, Opaque

12 mm (calibrated)

$ 78.70

View Gem

5.42ct Brown Smoky Quartz, Round, VVS

12 mm (calibrated)

$ 14.85

View Gem

7.77ct White Quartz Cat'S Eye, Round, Transparent

12 mm (calibrated)

$ 27.67

View Gem

5.58ct Brown Smoky Quartz, Round, VVS

12 mm (calibrated)

$ 30.57

View Gem

5.29ct Yellow Quartz, Round, VVS

12 mm (calibrated)

$ 21.26

View Gem

9.10ct Multicolor Agate, Round, Opaque

12 mm (calibrated)

$ 8.62

View Gem

4.67ct Brown Smoky Quartz, Round, VVS-VS

12 mm (calibrated)

$ 7.68

View Gem

8.27ct Multicolor Agate, Round, Opaque

12 mm (calibrated)

$ 14.00

View Gem

6.28ctw Multicolor Pietersite, Round, Opaque

12 mm (calibrated)

$ 14.70

View Gem

5.27ct Brown Smoky Quartz, Round, VVS-VS

12 mm (calibrated)

$ 17.32

View Gem

5.20ct Yellow Quartz, Round, VVS-VS

12 mm (calibrated)

$ 28.49

View Gem

Why Buy Round Shape 12 Mm Gems from GemSelect?

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

Recomendado Totalmente Los Productos Se Entregaron A Tiempo

Posted By Alexis in May, 2026
Source: Bizrate

Overall Rating -> 10 star ratings

I can pick and choose from large selection and find just what I need for .y projects, currently my cane.

Posted By Darkstar731 in July, 2025
Source: Bizrate

Overall Rating -> 10 star ratings

The citrine gems are beautiful. I appreciated that each stone was individually shown on the website so I could see exactly what I was getting. No mystery person selecting random stones for me. The documentation included with each gem was high quality as well. Great price and arrived as expected.

Posted By Jen in December, 2025
Source: Bizrate

Overall Rating -> 10 star ratings

Love, and have always loved, your website.

Posted By Aberabic in July, 2025
Source: Bizrate

Overall Rating -> 10 star ratings

IT WAS GREAT SIMPLE I WAS ABLE TO MAKE AN ACCOUNT EASY AND WAS ABLE TO FAVORITE ALL OF MY FINAL SELECTED GEMS, I JUST LOVE IT.

Posted By YE in October, 2025
Source: Bizrate

Overall Rating -> 10 star ratings

On the clarity options it goes "and better" so if youre looking for si specifically and you click si and better it still shows you basically everything. It just removes the opaques. Itd be nice if it was vs only, vss only, si only, etc

Posted By Iamnotakrustykrab in December, 2025
Source: Bizrate
Enlarged Gemstone Image