10 Best gem testers of 2025

Explore top picks

Best Choice

1

Presidium
Presidium Instruments Gem Indicator (PGI) Handheld Tester for Identifying Diamonds and Common Colored Gemstones
Main highlights

Quick and Accurate Testing
The Presidium Gem Indicator offers fast results in under 6 seconds, ensuring accuracy with its retractable thermoelectric probe.

Ideal for Gem Enthusiasts
Perfect for identifying diamonds and 31 different gemstones, including rubies and sapphires.

Highly Praised for Versatility
Users appreciate its ability to test various gemstones and identify non-gem materials like glass.
Key specs
- Battery:USB port for power
- Dimensions:8.1 x 3.4 x 2.4 inches
- Testing Method:Handheld tester
- Weight:11.2 ounces
- Material:Chrome-brushed grip
9.7

Exceptional

Our Rating

8.0
Simple to use

8.0
worth the money

8.0
Precision
How do we rank?

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Based on millions of stores and reviews

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Value for Money

2

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.
9.6

Exceptional

Our Rating

8.2
Simple to use

8.0
Precision

8.0
worth the money
3

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.
9.5

Excellent

Our Rating

8.4
Durability

8.0
Simple to use

8.0
Precision
4

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
- Weight:4.2 ounces
- Material:N/A
9.3

Excellent

Our Rating

8.9
movability

8.0
Simple to use

8.0
worth the money
5

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.
9.0

Excellent

Our Rating

8.0
Simple to use

8.0
Precision

8.0
worth the money
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6

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
- Weight:3.52 ounces
- Material:Plastic
8.9

Very Good

Our Rating

8.0
worth the money

8.0
Precision

8.0
Simple to use
7

GTE
Gold Silver Jewelry Tester Appraisal Kit 10K 14K 18K 22K 24K Platinum Palladium Test Precious Metals 999 925 Scrap
Main highlights

Versatile Testing Kit
All-in-one kit determines karat of gold, silver, platinum.

Ideal for Jewelry Enthusiasts
Perfect for testing and appraising jewelry investments and scrap.

Highly Rated for Affordability
Praised for testing multiple metals at an affordable price.
Key specs
- Accuracy:Accurate
- Karat Range:Gold, Silver, Platinum
- Test Types:Gold, Silver, Platinum
- Power Source:N/A
- Portability:N/A
8.8

Very Good

Our Rating
8

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
8.6

Very Good

Our Rating
9

Hqdz
High Accuracy Professional Diamond Tester Pen Jeweler Tool for Novice and Expert - Diamond Selector II 9V Battery Included(Black)
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.
8.5

Good

Our Rating
10

TEKCOPLUS
Heavy Duty Calcite Dichroscope Gemstone Tester Trichoic Pleochroic Colors Gemstone Identification Gemstones Gemological Testing Diamond Jeweler Tool Metal Body Gemology
Main highlights

Mesmerizing Color Play
Experience the mesmerizing play of colors exhibited by gemstones and rough.

Ideal for Gem Identification
Helps in distinguishing stones of the same color from one another.

Sturdy and Accurate
Praised for being sturdy and accurate, making gem identification easier.
Key specs
- weight:1.44 ounces
- dimensions:3.23 x 1.26 x 1.22 inches
- magnification:N/A
- lens material:N/A
- handle material:N/A
8.2

Good

Our Rating

8.0
worth the money

8.0
Simple to use

10 Best gem testers of 2025

1

Presidium Instruments Gem Indicator (PGI) Handheld Tester for Identifying Diamonds and Common Colored Gemstones

8.0

8.0

8.0

How do we rank?

How do we rank?

Analyzing top stores

2

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

3

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

4

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

5

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

8.0

8.0

8.0

6

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

8.0

8.0

8.0

7

Gold Silver Jewelry Tester Appraisal Kit 10K 14K 18K 22K 24K Platinum Palladium Test Precious Metals 999 925 Scrap

8

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

9

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

10

Heavy Duty Calcite Dichroscope Gemstone Tester Trichoic Pleochroic Colors Gemstone Identification Gemstones Gemological Testing Diamond Jeweler Tool Metal Body Gemology

8.0

8.0

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