How to Judge Diamonds with a Loupe

January 02, 2020 - Jewelry & Luxury Items

How long has that diamond your grandmother gave you been sitting in your dresser drawer?

Big assets like this can come in handy when you need some quick cash and you’re not using them anyway. Most pawn shops will give you a pretty penny for your diamonds.

Before you head straight for your local pawn shop, however, make sure to expect your diamond under a diamond loupe. What is a loupe, you ask? Diamond loupes are a type of magnifying glass which help you assess the quality of diamonds.

Take a peek at your diamond first to assess the four Cs: carat, cut, color, and clarity.

Read on to learn more!

The Four Cs

The four Cs are widely considered to be the main telling facets of a diamond. A one-carat diamond with amazing clarity will cost even more than a three-carat diamond that’s super yellow.


Carat refers to the size of the diamond. Your average female considers a 2.4-carat diamond as big.

Big isn’t always better, though. Diamonds are known for their unique sparkling quality, and carat alone won’t ensure that. Larger diamonds are also rarer, so the price hikes up pretty quickly past one carat.


There are ten main diamond cuts your diamond will likely fall under:

  • Round
  • Oval
  • Princess
  • Radiant
  • Emerald
  • Pear
  • Ascher
  • Heart
  • Marquise
  • Cushion

There’s not a huge difference in price when it comes to cut alone, except when it comes to round diamonds. Round diamonds are typically more valuable because they have 58 facets.

The number of facets optimizes the prismatic effect of light entering the diamond. Since diamonds are made to sparkle, this ups their value pretty heftily.


The most valuable diamonds are crystal-clear and 100% devoid of color. This is pretty rare. Under your loupe, compare your diamond to stark white paper.

Diamond color is graded on a scale that the Gemological Institute of America came up with in the late 20th century. Today, it’s known as the GIA scale.


Clarity concerns any abrasions, inclusions, or blemishes on the diamond. Of course, the cleanest and clear diamonds are the rarest.

Under 10x magnification, do you see any dark spots on your diamond? How about a lighter spot that creates a rift in a clean-cut line? Keep your eye out for these when assessing clarity.

Clarity is also judged on a GIA scale. There are six categorizations. They go from “Included” to “Flawless.” Let’s hope yours is near the top!

From Home Diamond Loupe to Cash in Pocket

Inspecting your diamond under a diamond loupe is essential before you decide to sell your diamond for some quick cash. A diamond magnifier can help you determine the ballpark worth of your diamond ahead of time. Make sure you get a good deal by heading to the pawn shop prepared!

Ready to get selling? At PawnGuru, all you need to do is upload a photo to get estimates from multiple pawn shops near you. Get starting pawning or selling your diamonds today!

David Stiebel
David Stiebel

David Stiebel is one of the cofounders of PawnGuru. David was educated at MIT, where he studied Math. He subsequently worked at Bain as a data scientist before starting PawnGuru in 2015. He started PawnGuru to build a better tool for pawn shops and consumers to connect.

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