Updated:29 September 2026
Rank 1-17 of the best Diamond Testers
Our recommendation Price Customer rating
1. Comparison winner
Diamond Tester with UV Light - Professional Diamond Selector for Retail Jewellers, Pawn Brokers and Chain Stores
Diamond Tester with UV Light - Professional Diamond Selector for Retail Jewellers, Pawn Brokers and Chain Stores
Available immediately
free shipping
  • lightweight and compact design for easy transport and storage
  • single device with multiple functions to reduce the need for separate tools
  • calibration option to adjust and verify measurement accuracy over time
Our rating
9,9
very good
2. Best value
JSP GTE Digital Diamond and Gem Purity Tester Kit for Diamonds, Moissanite, Gold, Silver and Platinum Jewellery
JSP GTE Digital Diamond and Gem Purity Tester Kit for Diamonds, Moissanite, Gold, Silver and Platinum Jewellery
Available immediately
free shipping
  • portability: a portable electronic jewellery tester and a 30x triplet magnifier for on the go jewellery testing
  • multifunctionality: determines karat values for gold and checks the purity of silver and platinum, and helps identify if a gemstone is a real diamond
  • ease of use: very easy to operate with simple instructions, a clear lcd display and audible indicators
Our rating
9,8
very good
Professional Diamond Tester - Portable High Accuracy Tool
Professional Diamond Tester - Portable High Accuracy Tool
Available immediately
free shipping
  • easy to carry with portable design
  • distinguishes natural diamonds from imitations
  • equipped with sounds and lights for simple identification
Our rating
9,8
very good
TALOEYH Diamond Tester Pen – Portable Gemstone Hardness Tester (Black)
TALOEYH Diamond Tester Pen – Portable Gemstone Hardness Tester (Black)
Available immediately
free shipping
  • portability: lightweight design makes it easy to carry and store
  • multifunctionality: combines several measurement modes in one device to cover common tasks
  • calibration: allows quick recalibration to maintain accuracy
Our rating
9,8
very good
5. Bestseller
HMKIS Diamond Tester Pen with 60x LED Magnifier and Thermal Conductivity Meter
HMKIS Diamond Tester Pen with 60x LED Magnifier and Thermal Conductivity Meter
Available in a few days
free shipping
  • compact and lightweight so the device is easy to carry and store
  • offers multiple functions in a single device for versatile use
  • calibration option allows adjusting accuracy for different conditions
Our rating
9,6
very good
Presidium DiamondMate-C Electronic Diamond Tester
Presidium DiamondMate-C Electronic Diamond Tester
Available in a few days
free shipping
  • portability enables easy carrying thanks to a compact lightweight design
  • multifunctionality combines several useful functions in one device for versatile use
  • calibration capability enables precise readings by allowing adjustments
Our rating
9,6
very good
Diamond Tester Pen with Mini Jewelry Scale and LED Magnifying Glass
Diamond Tester Pen with Mini Jewelry Scale and LED Magnifying Glass
Available immediately
free shipping
  • : detect if a gemstone is real or fake, including diamond, sapphire, ruby, crystal, agate, jadeite, and other precious stones of various sizes
  • scale can be calibrated for accuracy
  • simple to operate with professional accuracy, no expert knowledge required
Our rating
9,6
very good
Diamond Tester Pen – Portable Electronic Gemstone and Jewellery Tester, High-Accuracy, Multi-Gemstone
Diamond Tester Pen – Portable Electronic Gemstone and Jewellery Tester, High-Accuracy, Multi-Gemstone
Available immediately
free shipping
  • compact and lightweight design for easy portability
  • multiple measurement modes and functions in one device
  • calibration option to adjust measurement accuracy
Our rating
9,6
very good
Electronic Diamond Tester Pen with Magnifiers
Electronic Diamond Tester Pen with Magnifiers
Available immediately
free shipping
  • compact and portable design for on-the-go testing and observation
  • tests authenticity of diamonds and hardness of gemstones like jade, crystal, and agate
  • easy-to-read display with clear LED lights and audio feedback for quick results
Our rating
9,6
very good
Professional Diamond Tester Pen With Two 30×/60× Magnifiers And A Mini LED Foldable Magnifier
Professional Diamond Tester Pen With Two 30×/60× Magnifiers And A Mini LED Foldable Magnifier
Available immediately
free shipping
  • Portability: lightweight and compact design making it easy to carry and store
  • Multifunctionality: multiple features in one device to handle common tasks
  • Calibration capability: option to calibrate for consistent measurements
Our rating
9,5
very good
Diamond Tester Pen with 30X Magnifier
Diamond Tester Pen with 30X Magnifier
Available immediately
free shipping
  • portable design for easy handling during testing
  • multi-functional with 30x magnification for detailed inspection of gemstones and other small items
  • simple to use with intuitive LCD display and LED indicators for straightforward interpretation
Our rating
9,3
good
Portable Diamond Tester Pen Kit with Gemstone Detector
Portable Diamond Tester Pen Kit with Gemstone Detector
Available immediately
free shipping
  • portable lightweight design enables easy carrying in a pocket or tool bag for on-the-go testing
  • identifies multiple gem materials beyond diamonds, providing versatile gemstone verification for daily use
  • easy to use with clear LED indicators and audible beeps, designed for beginners
Our rating
9,3
good
Weytoll Diamond Tester Pen
Weytoll Diamond Tester Pen
Available immediately
free shipping
  • lightweight and compact design makes it easy to carry and store
  • offers multiple functions like diamond testing and identifying simulants
  • simple to operate with a straightforward turn-on and ready process
Our rating
9,1
good
QWORK Diamond Tester with LED Light and Audio Indicator
QWORK Diamond Tester with LED Light and Audio Indicator
Available immediately
free shipping
  • portable with lightweight and durable plastic housing
  • detects multiple gemstones such as diamond, sapphire, crystal, agate and jadeite
  • #DELETED#
Our rating
9,0
good
Portable Diamond & Moissanite Tester Pen High-Accuracy Gemstone Detector
Portable Diamond & Moissanite Tester Pen High-Accuracy Gemstone Detector
Available immediately
free shipping
  • Portability: easy to carry and store thanks to a light, compact body
  • Multifunctionality: provides multiple measurement modes in one device
  • Calibration capability: enables calibration to maintain accurate readings
Our rating
8,9
good
50+ purchases last month
CalmGeek Diamond Tester Pen
CalmGeek Diamond Tester Pen
Available immediately
free shipping
  • handheld design for easy portability
  • ideal for various tasks such as measuring or weighing
  • calibrate for accurate and reliable performance
Our rating
8,6
good
Portable Diamond Tester Pen - High-Accuracy Moissan Diamond Detector for Gemstones (Sapphire, Ruby, Agate, Jade, Crystal)
Portable Diamond Tester Pen - High-Accuracy Moissan Diamond Detector for Gemstones (Sapphire, Ruby, Agate, Jade, Crystal)
Available immediately
free shipping
  • Portability: compact and lightweight design for easy carrying on the go
  • Multifunctionality: supports multiple measurement modes to handle different tasks
  • Calibration option: lets you calibrate the device to maintain accuracy
Our rating
8,6
good

Similar Diamond Tester comparisons

Diamond Testers buying guide: How to choose the right product from the above Diamond Testers test or comparison

Understanding Diamond Testers: How They Work and Why You Need One

What is a Diamond Tester?

A diamond tester is a handy tool that helps you determine whether a stone is a genuine diamond or a simulant, like cubic zirconia or moissanite. It works by measuring the thermal conductivity of the stone. Diamonds are excellent heat conductors, which means that when you press the tip of the tester against the stone, it will register a specific temperature reading. If it shows a high reading, you likely have a real diamond on your hands. For us, having a diamond tester can be essential, especially if we frequently deal with gemstones, whether for personal purchases or as professionals.

Why You Need a Diamond Tester

Imagine you’re at a market, looking at sparkling pieces of jewellery. It’s thrilling, but how do you know if you’re purchasing the real deal or a cleverly crafted imitation? A diamond tester can provide peace of mind, allowing us to confirm the authenticity of our purchases right on the spot. This tool is especially useful if we’re investing in high-value items or selling gemstones ourselves, as it adds credibility and trustworthiness to our transactions.

Key Features to Consider When Buying a Diamond Tester

Accuracy and Speed

When exploring diamond testers, we need to consider their accuracy and how quickly they can provide results. A reliable tester should give consistent readings within seconds, allowing us to make swift decisions without waiting around. Some testers also feature LED indicators, which make it easier to interpret the results quickly, ensuring we can confidently verify authenticity.

Type of Tester

There are various types of diamond testers available, ranging from handheld pen-style devices to more comprehensive electronic testers. If we’re looking for something simple, a pen tester is compact and easy to use. However, if our needs are more advanced, an electronic tester may offer additional features, like testing for other gemstone types or having built-in reference guides.

Portability and Design

For those of us who attend gem shows or markets frequently, portability is crucial. We should look for testers that are lightweight and easy to carry around. A pen-style tester or a small handheld device usually fits well into our bags and allows us to test stones on the go. The design should also be user-friendly, with clear buttons and displays.

Top Diamond Testers on the Market: Our Recommendations

Affordable Options for Everyday Use

For those of us on a budget, a basic handheld diamond tester could suffice. Models such as the gemOro Ultra Tester offer great value without sacrificing accuracy. It’s simple, user-friendly, and works well for quick checks.

Advanced Testing Tools

If we’re looking for something more sophisticated, we might consider the Presidium ADT. This tester is known for its speed and accuracy, providing results in mere seconds. With capabilities to differentiate between diamonds and other gemstones, it’s ideal for more serious gem enthusiasts or professionals.

All-in-One Testing Devices

For comprehensive testing needs, the gemOro Tester II provides a 3-in-1 solution. Besides testing for diamonds, it can test for moissanite and other gemstones, making it perfect for our collection or resale purposes. This versatile device can save us time and money by consolidating our testing needs into a single tool.

How to Use a Diamond Tester Effectively: A Step-by-Step Guide

Prepare the Tester and the Stone

Before we start testing, it’s important to prepare both the diamond tester and the gemstone. First, turn on the device and give it a moment to warm up, as recommended by the manufacturer. Next, clean the stone to ensure nothing interferes with the results. A quick wipe with a soft cloth usually suffices.

Testing Process

To test the stone, we simply place the tip of the tester against the surface of the gemstone, applying gentle pressure. We should ensure the tester is in full contact with the stone for an accurate reading. Once in place, the tester will emit a sound or display a light, indicating whether the stone is a diamond or not.

Interpreting the Results

Most testers will have a straightforward indicator system: a light or sound indicates a diamond, while a different signal indicates a simulant. If we receive a negative result but still have doubts, it might be worth running the test again or verifying with a more advanced tester.

Maintaining Your Diamond Tester for Longevity and Accuracy

Regular Cleaning and Storage

To keep our diamond tester in optimal condition, regular cleaning is essential. After each use, we should gently wipe the tip to remove any dust or residue. When not in use, it’s best to store the device in a protective case to prevent scratches or damage.

Battery Maintenance

If our diamond tester runs on batteries, it’s wise to replace them regularly or keep spares handy. Diminished battery power can affect the tester’s performance and accuracy. We should always ensure our device is fully powered before taking it with us for testing.

Table of contents
  1. Understanding Diamond Testers: How They Work and Why You Need One
  2. Key Features to Consider When Buying a Diamond Tester
  3. Top Diamond Testers on the Market: Our Recommendations
  4. How to Use a Diamond Tester Effectively: A Step-by-Step Guide
  5. Maintaining Your Diamond Tester for Longevity and Accuracy

Overview

1. Comparison winner
Diamond Tester with UV Light - Professional Diamond Selector for Retail Jewellers, Pawn Brokers and Chain Stores
Our rating
9,9
very good
Diamond Tester with UV Light - Professional Diamond Selector for Retail Jewellers, Pawn Brokers and Chain StoresAvailable immediately
2. Best value
JSP GTE Digital Diamond and Gem Purity Tester Kit for Diamonds, Moissanite, Gold, Silver and Platinum Jewellery
Our rating
9,8
very good
JSP GTE Digital Diamond and Gem Purity Tester Kit for Diamonds, Moissanite, Gold, Silver and Platinum JewelleryAvailable immediately
Professional Diamond Tester - Portable High Accuracy Tool
Our rating
9,8
very good
Professional Diamond Tester - Portable High Accuracy ToolAvailable immediately
TALOEYH Diamond Tester Pen – Portable Gemstone Hardness Tester (Black)
Our rating
9,8
very good
TALOEYH Diamond Tester Pen – Portable Gemstone Hardness Tester (Black)Available immediately
5. Bestseller
HMKIS Diamond Tester Pen with 60x LED Magnifier and Thermal Conductivity Meter
Our rating
9,6
very good
HMKIS Diamond Tester Pen with 60x LED Magnifier and Thermal Conductivity MeterAvailable in a few days
Presidium DiamondMate-C Electronic Diamond Tester
Our rating
9,6
very good
Presidium DiamondMate-C Electronic Diamond TesterAvailable in a few days
Diamond Tester Pen with Mini Jewelry Scale and LED Magnifying Glass
Our rating
9,6
very good
Diamond Tester Pen with Mini Jewelry Scale and LED Magnifying GlassAvailable immediately
Diamond Tester Pen – Portable Electronic Gemstone and Jewellery Tester, High-Accuracy, Multi-Gemstone
Our rating
9,6
very good
Diamond Tester Pen – Portable Electronic Gemstone and Jewellery Tester, High-Accuracy, Multi-GemstoneAvailable immediately
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Our tests and comparisons are objective and fact-based. Manufacturers have no influence on the ratings. We aim to provide greater transparency in the market, thereby promoting product quality.
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In our tests & comparison tables, we only include products that meet our minimum standards. This ensures that you can find the perfect product for your needs from a wide selection.
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