EXPERT TIPS FOR CHOOSING THE RIGHT DIAMOND TESTER PEN FOR JEWELERS

Identifying real and synthetic diamonds has never been more important, especially as moissanite and other simulants are becoming increasingly similar to natural diamonds. To ensure transparent transactions and accurate valuation, jewelers and jewelry stores need a professional diamond tester that offers fast, reliable, and easy-to-use verification. In this article, DC Technologies shares essential tips for choosing the right diamond testing pen—helping you select the device that best fits your work requirements, maximizes efficiency, and minimizes the risk of inaccurate results.

I. What is a diamond tester pen?

A diamond tester (also known as a diamond testing pen) is a specialized device used to quickly and easily distinguish real diamonds from simulants by measuring their electrical and thermal conductivity. Designed as a compact, handheld tool, it allows users to carry and operate it conveniently in various locations.

This highly practical instrument provides both speed and accuracy, making it invaluable for jewelers as well as individuals who want to verify the quality and authenticity of a diamond worth hundreds of millions.

II. Popular types of diamond tester pens today

1. Presidium Adamas

Presidium Adamas is one of the most reliable high-end diamond testers in the jewelry industry, combining thermal conductivity measurement, electrical conductivity testing, and advanced signal-processing algorithms.

Its most outstanding advantage is the removable and replaceable Magnetic Probe Tip, which automatically activates calibration mode to ensure maximum accuracy over long-term use. The ultra-sensitive probe, together with the chrome anti-slip metal plate, allows jewelers to test even very small diamonds with precision while minimizing false readings on moissanite or other simulants.

The Adamas tester features quick start-up, clear LED indicators for different gemstone categories, low-battery alerts, and an automatic shut-off after 2 minutes of inactivity to extend battery life.

Presidium Adamas is the ideal diamond testing device for jewelry stores, gemological laboratories, and professional jewelers who require a highly stable, ultra-sensitive tester that delivers consistent accuracy in all conditions.

2. Moissanite Tester II

The Presidium Moissanite Tester II is specifically designed to distinguish Moissanite from Diamond using a highly stable electrical conductivity measurement principle. Its key advantages include:

– Special polymer probe tip with high sensitivity, ideal for testing small stones or mounted jewelry.

– Operates based on the fact that moissanite conducts electricity while diamond does not, delivering accurate results in just 1–2 seconds.

– Optimized for jewelers to perform quick in-store testing, with a clear LED display that indicates moissanite through the “SIMULANT” light and a short audible alert.

– Built with a lightweight, durable design, low power consumption, and powered by three AAA batteries, providing approximately 2.5 hours of continuous operation.

The Presidium Moissanite Tester II is therefore an efficient and economical choice for jewelry stores that need a reliable tool to identify moissanite accurately before conducting more advanced testing methods.

3. Presidium SAM

Presidium SAM is a versatile diamond tester that integrates both thermoelectric and electrical conductivity technologies, allowing users to distinguish diamond, moissanite, and simulants with a single device. With its high-precision technology, the Presidium SAM offers several outstanding advantages:

– Equipped with an ultra-fine 0.45 mm probe tip, one of the thinnest in the gem-testing industry, enabling accurate testing of very small stones from 0.01 ct.

– Features next-generation moissanite detection technology, capable of identifying even low-electrical-conductivity moissanite, which older testers often fail to detect.

– Built-in metal alert system helps users avoid inaccurate readings when the probe accidentally touches the stone setting or any metal part of the jewelry.

– Designed with a 180° multi-directional LED display, ensuring visibility from all angles—perfect for professionals working continuously.

This makes the Presidium SAM an ideal choice for experts who require high reliability, fast performance, and comprehensive stone identification.

III. Expert tips for choosing the right diamond tester pen for jewelers

1. Choose based on your work requirements

Each jewelry store, workshop, or gem-testing center has different requirements.

If you frequently need to distinguish diamond, moissanite, and simulants across various types of jewelry, a multi-functional tester such as the Presidium PMUT III is the ideal choice.

If your needs are simpler and you only want to differentiate moissanite from diamond, you can opt for a tester designed specifically for that purpose.

Clearly defining your goals before purchasing helps optimize costs while ensuring maximum testing efficiency.

2. Check the accuracy of the device

A reliable diamond tester must deliver high consistency, meaning the results should remain stable and repeatable on the same stone, even on small stones or those already mounted in jewelry.

You should choose a tester capable of distinguishing natural diamonds from simulants, while also identifying common substitutes such as Moissanite and CZ. Always review the technical specifications and consult expert evaluations before making a purchase decision.

3. Choose reputable brands

There are many diamond testers on the market, but not all of them are reliable. Long-established brands trusted within the jewelry industry those with a clear verification history, proper user instructions, and strong after-sales support are always the safest choice.

Reputable brands typically offer genuine products with clear warranty policies and technical assistance. Choosing a well-known manufacturer ensures accurate testing performance, long-term durability, and consistent reliability.

4. Consider safety and durability

Since jewelers may use a diamond tester multiple times a day, the device needs to be highly durable, with a sturdy design that can withstand light impacts and frequent use.

Additionally, features such as metal-touch alerts are essential to prevent measurement errors, especially when testing diamonds already set in jewelry.

A reliable diamond tester should have a strong casing, a durable sensor tip, and ensure safety during continuous use. Replaceable probes, long-lasting batteries, and low power consumption are also important factors to consider for a device that will be a long-term companion in daily work.

5. Select a price point that fits your budget

Price is also an important factor. Jewelers need to balance features, accuracy, and budget to choose a diamond tester that is effective while remaining cost-efficient.

IV. Tips for using a diamond tester pen for the most accurate results

1. Ensure the stone is clean

Before testing, clean the diamond’s surface to remove dust, oil, or any dirt. This ensures direct contact with the tester and improves measurement accuracy.

2. Use the correct probing technique

Place the tester tip gently on the surface of the stone and hold it steady for a few seconds, following the manufacturer’s instructions. Avoid pressing too hard or moving the tester during measurement to prevent inaccurate results.

3. Test multiple points on the stone

To ensure accuracy, check multiple points on the diamond, especially for larger stones or those with complex cuts.

4. Pay attention to temperature and environmental conditions

Diamond testers work best at room temperature. Avoid testing stones that are too hot or too cold, and minimize testing in humid or dusty environments.

5. Perform regular maintenance and calibration

Regularly clean the tester tip and perform calibration according to the manufacturer’s instructions. Routine maintenance helps ensure long-term accuracy.

V. Where to buy genuine diamond tester pens?

DC Technologies is a leading distributor of diamond testers and professional diamond testing equipment in Vietnam. With over 5 years of experience providing LAB solutions for the jewelry industry, DC Technologies is committed to delivering high-quality products with clear origins, directly imported from reputable brands such as Presidium and OGI.

When purchasing from DC, customers are guaranteed:

– 100% genuine products with full documentation and warranty.

– Detailed usage guidance from a technical team with 5–20 years of industry experience.

– Lifetime technical support, promptly resolving any arising issues.

– Competitive pricing and nationwide delivery, suitable for jewelers, jewelry stores, and individual buyers.

DC Technologies is the trusted choice for owning accurate, durable, and internationally standard diamond testers.

Conclusion

Choosing the right diamond tester not only helps jewelers achieve higher accuracy in their inspections but also ensures professionalism and credibility in their work. By understanding your needs, technical requirements, and reputable brands, you can easily select the device that best meets your demands. If you are looking for a genuine, durable, and highly accurate diamond tester, DC Technologies is a trusted provider, offering a full range of products from leading global manufacturers. Investing wisely from the start will help you optimize costs, improve efficiency, and maintain reliable testing quality in the long term.

References

What is a diamond tester?