10 Best gem testers of 2025

Explore top picks

Best Choice

1

Presidium
Presidium Instruments Gem Tester II (PGT II) with Assisted Thermal Calibration (ATC) for Identifying Diamonds/Moissanites and Common Colored Gemstones
Main highlights

Compact Design and Portability
Redesigned to be more compact, sturdy, and portable for easy use.

Ideal for Gemstone Identification
Perfect for identifying diamonds, moissanites, and common colored gemstones.

Reliable Performance
Praised for providing consistent and reliable results in gemstone testing.
9.8

Exceptional

Our Rating

8.2
Simple to use

8.0
Precision

8.0
worth the money
How do we rank?

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Based on millions of stores and reviews

Shoppers influence our rankings
Analyzing top stores
Value for Money

2

Presidium
Presidium Instruments Gem Tester II (PGT II) Now with Assisted Thermal Calibration (ATC) for Identifying Diamonds/Moissanites and Common Colored Gemstones
Main highlights

Compact and Portable Design
Redesigned to be more compact, sturdy, and portable.

Ideal for Jewelry Sellers
Perfect for identifying real stones in jewelry business.

Consistent and Reliable Results
Consistently praised for accurate gemstone identification.
9.7

Exceptional

Our Rating

8.4
Durability

8.0
Simple to use

8.0
Precision
3

HMKIS
HMKIS Diamond Tester Pen, Professional Jewelry Diamond Tester with 60X Jewelry Loupe Magnifier, Diamond Selector for Novice and Expert (Non-Rechargeable)
Main highlights

High Accuracy Testing
The diamond tester provides reliable results, distinguishing diamonds from imitations with thermal conductivity.

Ideal for Novice and Expert
Suitable for both beginners and professionals in jewelry testing and inspection.

60X Magnification Praised
Customers appreciate the included 60X LED magnifier for detailed examination.
Key specs
- Battery:1 9V battery included
- Dimensions:10.16 x 2.17 x 1.38 inches
- Testing Method:Beeping sound alerts
- Sound Alert:Beeping-beeping-beeping
- Weight:4.2 ounces
9.5

Excellent

Our Rating

8.9
movability

8.0
Simple to use

8.0
worth the money
4

SmartPro
SmartPro SPGE-I Gem Eye I Gem and Diamond Tester Smart Pro
Main highlights

High Efficiency and Versatility
High efficiency with the thinnest probe tip for precise testing of diamonds as small as 0.01ct.

Ideal for Jewelry Professionals
Perfect for jewelry resellers and gem enthusiasts needing portable, accurate testing anywhere.

Self-Calibrating Feature Praised
Customers appreciate the self-calibration feature, enhancing accuracy despite temperature sensitivity.
9.2

Excellent

Our Rating

8.0
Simple to use

8.0
Precision

8.0
worth the money
5

Siziviki
Diamond Tester, Professional Jewelers' Gemstone Detector, High Accuracy Diamond Tester Pen Professional (Metal Detection Limitation)
Main highlights

Quick and Easy Testing
Detects authenticity of diamonds, jade, agate, and crystal quickly.

Ideal for Jewelry Verification
Perfect for verifying gemstones in watches and jewelry.

Ease of Use Praised
Customers appreciate its simplicity and effectiveness in operation.
Key specs
- Battery:9V, not included
- Dimensions:5.31L x 0.87W x 1.57H
- Testing Method:Sound alert above 9
- Sound Alert:Yes
- Weight:3.52 ounces
9.1

Excellent

Our Rating

8.0
worth the money

8.0
Precision

8.0
Simple to use
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6

Lumirio

Lumirio Gemstones UV Flashlight, Super Bright Gem Tester for All Stones, Rechargeable Jade Jewelry Test Light, Yellow White UV 365nm 395nm Flashlight for Gem Stones Wooden Jewelry
8.9

Very Good

Our Rating
7

GTE
Purity Testing Kit for Diamonds Gemstones Moissanites Gold Silver and Platinum Jewelry Electronic Digital Diamond Tester Machine JSP GTE
Main highlights

Comprehensive Testing Kit
Includes tools for testing gold, silver, platinum, and diamonds.

Ideal for Jewelry Enthusiasts
Perfect for those investing in or evaluating precious metals and stones.

Highly Rated Diamond Tester
Customers praise the diamond tester for its accuracy and reliability.
Key specs
- Accuracy:Fast and accurate
- Karat Range:Gold, Silver, Platinum
- Test Types:Jewelry testing
- Power Source:N/A
- Portability:N/A
8.7

Very Good

Our Rating
8

Valkynos

Valkynos Professional Diamond Tester Pen with 365nm UV Light & Thermal Sensor – Fast 0.5s Detection, Portable Gem Checker for Novice & Experts – Battery Included
8.4

Good

Our Rating
9

Hqdz-td

Diamond Tester,Jewelry Diamond Tester Pen+200g/0.01g Mini Jewelry Scale＋60X Mini LED Magnifying, Professional Diamond Selector for Novice and Expert,Thermal Conductivity Meter(Diamond Tester +)
8.1

Good

Our Rating
10

Hqdz
Diamond Tester,High Accuracy Jewelry Diamond Tester Professional Diamond Tester Pen Jeweler Tool for Novice and Expert - Diamond Selector II 9V Battery Included(Black Diamond Testers)
Main highlights

Quick and Precise Testing
Professional Diamond Selector II offers fast, accurate, and safe diamond identification.

Ideal for Home Use
Perfect for checking jewelry at home or small-scale evaluations.

Highly Praised for Accuracy
Customers appreciate its ability to distinguish real diamonds from fakes effectively.
8.0

Good

Our Rating

10 Best gem testers of 2025

1

Presidium Instruments Gem Tester II (PGT II) with Assisted Thermal Calibration (ATC) for Identifying Diamonds/Moissanites and Common Colored Gemstones

8.2

8.0

8.0

How do we rank?

How do we rank?

Analyzing top stores

2

Presidium Instruments Gem Tester II (PGT II) Now with Assisted Thermal Calibration (ATC) for Identifying Diamonds/Moissanites and Common Colored Gemstones

8.4

8.0

8.0

3

HMKIS Diamond Tester Pen, Professional Jewelry Diamond Tester with 60X Jewelry Loupe Magnifier, Diamond Selector for Novice and Expert (Non-Rechargeable)

8.9

8.0

8.0

4

SmartPro SPGE-I Gem Eye I Gem and Diamond Tester Smart Pro

8.0

8.0

8.0

5

Diamond Tester, Professional Jewelers' Gemstone Detector, High Accuracy Diamond Tester Pen Professional (Metal Detection Limitation)

8.0

8.0

8.0

6

Lumirio Gemstones UV Flashlight, Super Bright Gem Tester for All Stones, Rechargeable Jade Jewelry Test Light, Yellow White UV 365nm 395nm Flashlight for Gem Stones Wooden Jewelry

7

Purity Testing Kit for Diamonds Gemstones Moissanites Gold Silver and Platinum Jewelry Electronic Digital Diamond Tester Machine JSP GTE

8

Valkynos Professional Diamond Tester Pen with 365nm UV Light & Thermal Sensor – Fast 0.5s Detection, Portable Gem Checker for Novice & Experts – Battery Included

9

Diamond Tester,Jewelry Diamond Tester Pen+200g/0.01g Mini Jewelry Scale＋60X Mini LED Magnifying, Professional Diamond Selector for Novice and Expert,Thermal Conductivity Meter(Diamond Tester +)

10

Diamond Tester,High Accuracy Jewelry Diamond Tester Professional Diamond Tester Pen Jeweler Tool for Novice and Expert - Diamond Selector II 9V Battery Included(Black Diamond Testers)

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