Wondering How to Use a Jeweler’s Loupe? Here are 10 Simple Steps

Merit is a spirited writer having the time of her life. She loves to collect cute bracelets…

Buying jewelry is much easier when you have a jeweler’s loupe. It can save you the heartache of buying a fake gemstone at the price of a real one — but only if you know how to use it. In this article, we’ll show you how to use a jeweler’s loupe to detect an authentic piece of jewelry and avoid getting ripped off. 

How do loupes work?

Diamond Cut Loupe

A loupe is a usually small glass used for making tiny details in a gemstone appear larger. 

💡 Loupe vs Magnifying Glass? Loupes are different from magnifying glasses because they are smaller and require you to place them close to your eye. 

A loupe works by making tiny details in gemstones bigger so you can see cracks, inclusions, or chips typical of a gemstone. They also help you see the setting of a gemstone within a metal.  

When do people need to use a loupe?

A loupe is a must-have when buying gemstones. By enlarging small details, a loupe can help you differentiate a genuine gemstone from a fake one. 

By using a loupe when shopping for jewelry, you’ll be able to: 

  • Easily identify a real gemstone. Genuine gemstones will have tiny cracks and imperfections when you check them under a loupe.  
  • Know whether you can trust a specific jeweler. A trusted jeweler will have a loupe that they use. They’ll also not hesitate to let you use your loupe when buying from them and may even guide you through using it. 
  • Buy the exact gemstone you want, whether it’s a diamond or a diamond simulant like cubic zirconia

However, to use a loupe successfully, you need to know the characteristics of a real gem and look out for them. 

How to Use a Jeweler’s Loupe 

Since a jeweler’s loupe is crucial to successfully shopping for gemstones, you should learn how to use one. You can inspect a gemstone with a loupe by following this step-by-step guide: 

  1. Clean your gemstone 
  2. Unfold the loupe
  3. You’ll find a finger slot on the part of the loupe opposite the glass; insert your index finger here. 
  4. Bring the loupe close to your eye so your thumb can touch and rest on your cheek. 
  5. Use your free hand to bring your gemstone close to the loupe. To ensure that it stays close enough, let the free fingers from both of your hands meet each other. 
  6. Set the gemstone to stay in focus (that is, directly under the loupe lens). 
  7. Do not shake the hand holding the loupe. If you find that your hands are shaky, place your elbow on a table, so it stays steady. 
  8. Now, examine the jewelry. You may turn the gem around to enable you see it from different angles. 
  9. Look for inclusions, chips, and other details that characterize the gemstone you’re hoping to buy. 
  10. Once you’ve checked to your satisfaction, remove your index finger and fold back the loupe. 

With repeated use, you’ll be able to use a jeweler’s loupe easily. 

Do you close one eye when using a loupe?

Closing one eye does not improve how well you can see through a loupe. Instead, it could cause a strain on the closed eye and give you a headache, especially if you have to use the loupe for a long time. It’s best to keep both eyes open when using a loupe.

How can you tell a diamond from a loupe?

You can tell by doing a loupe test. 

First, place the diamond under your loupe, as we explained earlier. Real diamonds usually contain inclusions (small minerals trapped within the diamond during its formation). When you check a diamond through a loupe, you should see these minerals shaped like clouds, crystals, or feathers within the diamond. 

Which magnifying power should you buy?

Loupes come in different magnifying powers. The magnifying power indicates how much a loupe increases the size of each detail in a gemstone. For example, a 10x loupe means that the loupe will help you see each detail ten times larger than its actual size. 

The most commonly available are the 10x, 20x, and 30x magnifying powers. So which magnifying power should you get?  

10x Magnifying Loupe 

 10x Magnification Jewelers Eye Loupe

A 10x loupe is the most common loupe used by gemologists and the standard magnifying power for viewing gemstones.


  • It’s cheaper than other types of loupes.
  • It’s more comfortable to use than other magnifying powers. You can place your gemstone about 2.5cm away from the loupe.
  • You can view a wide area of your gemstone at a comfortable distance. 


  • While details are enlarged enough for you to see, they don’t look as large as when checked with higher magnifying power loupes.

20x Magnifying Loupe 

BlueDot Trading Mini 20 x 21mm Metal Folding Jeweler Loupe Eye Magnifier Magnifying Glass Triplet for Coin & Stamp Collectors, Reading Fine Print, Maps, and Jewelry Identification

With a 20x loupe, you get a closer view of the gemstone. This type helps you see gemstone details 20 times larger than their original size. 


  • You get a closer look at gemstone details compared to a 10x loupe.


  • It has a lower field of view, so you can’t view a wide area of the gemstone at once. 
  • You need a distance of about 1.25cm between your gemstone and a 20x loupe to use it. This short distance makes focusing more difficult. 

30x Magnifying Loupe 

Portable 30X Jewelers Loupe Magnifier - Double Deck Glass Magnifying Eye Loop Stand - Best for Jewelry Identifying Type, Diamonds, Coins, Miniatures, Engravings, Markings, Textile Fabric

This is the loupe with the highest magnifying power. It increases an image size by 30. 


  • It accentuates even the tiniest details.


  • You’ll need a UV light source to use a 30x loupe.  
  • It is hard to focus on a gemstone using a 30x loupe.
  • Real 30x loupes are usually more expensive. 

Generally, the higher the magnifying power of a loupe, the smaller the area it can view. 

Loupes are also differentiated based on the number of lenses they have. For example, a single loupe has only one lens, a doublet has two lenses combined, while a triplet (or triple loupe) has three lenses combined. 

💡 Keep in Mind: The more the number of lenses, the clearer the view a loupe provides. If you’re looking for a loupe that’s easy to use and provides a sharp, clear view, then a 10x triplet loupe is your best choice.  

Change Your Perspective with a Loupe

The jewelry market can be confusing for newbies. Even seasoned jewelry shoppers find it tough sometimes. A loupe is one of those simple tools that can make your gemstone shopping much easier and safer. 

So don’t hesitate to follow this guide on how to use a loupe when next you shop for gems — it could save you from buying a fake gemstone.  

💎 You should know: We use affiliate links throughout our site. This means we may earn a cent or two when you make a purchase on our site. Thanks for adding to our shine.