search
  • English speaking customer support only

    Toll Free - USA & Canada only:
    1-800-464-1640

    International:
    +66-39303404

  • Change Language
  • USD
Buy Customized Gemstone Lots

Buy Octagon Shape 20x15 mm Gems

Single

Pairs

Lots

Faceted

Cab

Gemtype Color Shape Weight Size Clarity Price Origin
You Selected (14): Octagon Shape 20x15 mm Gems Clear All
Sort By:
Click for Details
Compare
1 pc
Add to Cart
Black Gray Hematite Gem - 12.1ct Octagon Cabochon (ID: 498037)

Octagon / Emerald Cut Gray Hematite

12.1ct
20.2 x 15.3 mm
$ 10.12
Item in Stock
Click for Details
Compare
1 pc
Add to Cart
Black Gray Hematite Gem - 16.5ct Octagon Cabochon (ID: 498044)

Octagon / Emerald Cut Gray Hematite

16.5ct
19.8 x 15 mm
$ 13.86
Item in Stock
Click for Details
Compare
1 pc
Add to Cart
Black Gray Hematite Gem - 20.4ct Octagon Cabochon (ID: 498041)

Octagon / Emerald Cut Gray Hematite

20.4ct
19.8 x 14.8 mm
$ 17.13
Item in Stock
Click for Details
Compare
2 pcs
Add to Cart
Black Gray Hematite Gem - 18.4ct Octagon Cabochon (ID: 491900)

Octagon / Emerald Cut Gray Hematite

18.42 ct (total 36.84ctw)
19.2 x 14.6 mm
$ 32.79
Item in Stock
Click for Details
Compare
2 pcs
Add to Cart
Black Gray Hematite Gem - 18.8ct Octagon Cabochon (ID: 491895)

Octagon / Emerald Cut Gray Hematite

18.76 ct (total 37.51ctw)
19.5 x 14.9 mm
$ 33.38
Item in Stock
Click for Details
Compare
2 pcs
Add to Cart
Black Gray Hematite Gem - 17.4ct Octagon Cabochon (ID: 491893)

Octagon / Emerald Cut Gray Hematite

17.44 ct (total 34.87ctw)
19.4 x 15.1 mm
$ 31.03
Item in Stock
Click for Details
Compare
2 pcs
Add to Cart
Black Gray Hematite Gem - 20.6ct Octagon Cabochon (ID: 491902)

Octagon / Emerald Cut Gray Hematite

20.63 ct (total 41.25ctw)
19.8 x 15.1 mm
$ 36.71
Item in Stock
Click for Details
Compare
2 pcs
Add to Cart
Black Gray Hematite Gem - 20.3ct Octagon Cabochon (ID: 491896)

Octagon / Emerald Cut Gray Hematite

20.25 ct (total 40.49ctw)
20.2 x 15 mm
$ 36.04
Item in Stock
Click for Details
Compare
1 pc
Add to Cart
Lemon Quartz Gem - 34.1ct Octagon Step Cut (ID: 470082)

Octagon / Emerald Cut Yellow Quartz

34.1ct
19.9 x 14.7 mm
$ 35.82
Item in Stock
Click for Details
Compare
1 pc
Add to Cart
Black Gray Hematite Gem - 17.6ct Octagon Cabochon (ID: 515489)

Octagon / Emerald Cut Gray Hematite

17.6ct
19.7 x 14.4 mm
$ 17.55
Item in Stock
Click for Details
Compare
1 pc
Add to Cart
Black Gray Hematite Gem - 19.6ct Octagon Cabochon (ID: 515494)

Octagon / Emerald Cut Gray Hematite

19.6ct
20.6 x 15 mm
$ 19.55
Item in Stock
Click for Details
Compare
1 pc
Add to Cart
Black Gray Hematite Gem - 19.7ct Octagon Cabochon (ID: 515497)

Octagon / Emerald Cut Gray Hematite

19.7ct
19.9 x 15.2 mm
$ 19.67
Item in Stock
Click for Details
Compare
1 pc
Add to Cart
Violet Amethyst Gem - 30.6ct Octagon Step Cut (ID: 509140)

Octagon / Emerald Cut Violet Amethyst

30.6ct
19.9 x 15.2 mm
$ 214.27
Item in Stock
Click for Details
Compare
1 pc
Add to Cart
Black Gray Hematite Gem - 20.1ct Octagon Cabochon (ID: 515491)

Octagon / Emerald Cut Gray Hematite

20.1ct
20.6 x 14.8 mm
$ 20.06
Item in Stock
Octagon Shape 20x15 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 Octagon shape / Emerald-Cut, faceted and cabochon gems available now in 20 x 15 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.

Certified Customer Reviews
Overall Rating -> 10 star ratings
I would recommend GEMSELECT based upon the variety of gems. Gems that i didn't expect to even be apart of the selection and it gave me more options. Options in which played a key role in finding the right gem. Its always good to have options especially when trying to formulate a good piece of art work that has uniqueness. Which ultimately captures costumers eye appeal.
Posted By Left.Right.Center in February, 2019
Source: Bizrate
Overall Rating -> 10 star ratings
I found a beautiful rose quartz stone in the right size for the right price.
Posted By Calico9999 in February, 2019
Source: Bizrate
Overall Rating -> 10 star ratings
Gemselect is o.k the prices are pretty good, but the shipping prices really suck, one time I order from them and order got lost or never came, but they were good about fixing the problem and rectifying the situation, the stones and good, and the ones that come in the mail, look just as pictured on the website, or all it's not bad and its were I go to get my stones.
Posted By Spinach in February, 2019
Source: Bizrate
Overall Rating -> 10 star ratings
Perfect experience. Pictures were accurate, selection was easy to maneuver. Product arrived as ordered.
Posted By Jess in February, 2019
Source: Bizrate
Overall Rating -> 9 star ratings
Easy to shop through gemselect and will look there for future purchases.
Posted By Childcapo in February, 2019
Source: Bizrate
Overall Rating -> 10 star ratings
good value
Posted By Don in February, 2019
Source: Bizrate
Popular Gemstones
All Gemstones (143)
A B C D E F G H I J K L M O P Q R S T V Z
English speaking customer support only

Toll Free - USA & Canada only:
1-800-464-1640

International:
+66-39303404

Save Money
No shipping Fees for Additional Items!
$6.99 Worldwide Shipping

Update Translation
 
Current Value
New Value
GemSelect Gemstones
X Close Window
Colored Gemstones
X Close Window
Colored Gemstones
X Close Window
Colored Gemstones
Size and Weight

Gems are always measured in Millimeter (mm)

Dimensions are given as;
length x width x depth,
except for round stones which are;
diameter x depth

Select gems by size, not by weight!
Gem varieties vary in density, so carat weight is not a good indication of size

Note: 1ct = 0.2g

Size Comparison Chart