40 Carat Peridot (Cushion, 20.1×20.1mm, Yellowish Green)

Color:

yellowish green

actual size

Actual size is set for screen

How big is a 40 carat cushion-cut Peridot?

It depends on the cut parameters and length-to-width ratio, but a typical size of a 40ct square cushion-cut Peridot would be around 20.1×20.1 mm (±6%). Check how big it looks on a ring and finger.

Ring:

Gold
Platinum

Skin tone:

Pale
Light
Medium
Dark

Ring width: 3.0 mm

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64 mm

Your settings
Ring	Gold
Skin tone	Light
Ring diameter	16.9 mm
Ring width	3.0 mm
Finger length	64 mm
Finger coverage	119 %

Saved...

Ring diameter: 16.9 mm

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Additional Info

Peridot is quite an affordable gem, found naturally in yellowish-green or olive-green color. Ancient Egyptians called it "the gem of the sun". Dark olive-green gems are the most valued.

Where to buy?

For certified gemstones, high-end gemstone jewelry, and birthstone jewelry, see Blue Nile

Gem Details

Name:	Peridot
Mineral Group:	Olivine
Shape:	Cushion
Chemical Formula:	(Mg,Fe)₂SiO₄
Crystal Structure:	Orthorhombic
Hardness:	6.5
Specific Gravity	3.34
Carat weight:	40 ct
Gram weight:	8 g (0.2822 ounces)
Points:	4000 pts
Length:	20.1 mm
Width:	20.1 mm
Est. face-up size:	363.61 mm²
Volume:	2395.21 mm³
Length-to-width ratio:	1
Refractive Index:	1.65 - 1.69
Luster:	Vitreous
Wearability:	Very good
Care Instructions:	Should be worn gently
Color:	Peridot can be found in the following colors:
Birthstone:	Peridot is a birthstone for the month of August

Popular comparisons:

About Peridot Specific Gravity

Peridot has a specific gravity of approximately 3.32 - 3.37, with 3.34 being a generally accepted standard average for gem-quality material.

For all the Peridot size calculations on this website, the specific gravity of 3.34 is used.

To learn more about it and why it matters, and to compare densities of all the gemstones on one page, click here.

Ring & Finger Simulator

Use the simulator on this page to play around with different ring and finger configurations.

To select a different gemstone, shape, color or size, or to compare two gems side-by-side, use the form at the top of the page. Comparison example: 40ct Peridot vs Hiddenite (Cushion Cut)

If you want to compare cushion-cut Peridot sizes from 0.25 to 40ct on one page, see Cushion Cut Peridot Size Chart

In order to view real-world sizes on your screen, ensure that the actual size is set to your device screen size (diagonal in inches).