What Stones Will Pass a Diamond Tester?

When it comes to identifying real diamonds from their imitations, a diamond tester can be quite reliable. However, some stones can mimic the behavior of a real diamond and pass the test. Understanding these stones and knowing when to use more comprehensive testing methods can ensure the accuracy of your identification.

Understanding a Diamond Tester

A diamond tester is a tool widely used to determine whether a stone is a true diamond based on its thermal conductivity. Thermal conductivity is one of the key properties that differentiate a real diamond from its imitations. However, it's important to note that some stones can exhibit similar thermal conductivity and thus may pass the test. This article will explore several types of imitations that can pass a diamond tester and provide insights into more accurate identification methods.

Stones That Pass a Diamond Tester

1. Moissanite

Moissanite: This stone is known for its high thermal conductivity, which is very similar to that of a diamond. As a result, it can often be mistaken for a diamond by less sensitive testers. This makes moissanite one of the most common imitations to pass a diamond tester. Moissanite is formed naturally in meteorites but is more commonly created synthetically.

2. Cubic Zirconia (CZ)

Cubic Zirconia (CZ): Though CZ has lower thermal conductivity than diamonds, some less sensitive diamond testers might not differentiate it well from a real diamond. This imitation is frequently used as an alternative to diamonds due to its availability and affordability.

3. Synthetic Diamonds

Synthetic Diamonds: Lab-created diamonds have the same physical properties as natural diamonds and can pass a diamond tester without any issue. These diamonds are formed through advanced technology and are distinguishable from natural diamonds primarily through carbon isotope analysis.

4. White Sapphire

White Sapphire: While white sapphire does not exhibit the same thermal conductivity as diamonds, some less sensitive testers might register it as a diamond. White sapphire is a type of corundum, which is related to rubies and sapphires.

5. Certain Types of Glass

Certain Types of Glass: Some high-quality glass imitations can produce similar readings in a diamond tester. However, these imitations generally do not perform as well as diamonds. The presence of small air bubbles and a different refractive index can help differentiate these from true diamonds.

Accurate Identification Methods

To accurately determine whether a stone is a diamond, it's advisable to use more comprehensive testing methods. This includes:

Refractive Index Testing: Refractive index is one of the key distinguishing features of diamonds. Diamonds have a high refractive index, and other stones like moissanite and CZ do not. Fluorescence Features: Natural diamonds often fluoresce under ultraviolet light, while many imitations do not. Magnification Inspection: Under a microscope, you can look for inclusions and other natural characteristics that are unique to real diamonds.

Additional Information

A diamond tester will only positively identify a diamond and moissanite, making them the most reliable stones to pass the test. Synthetic moissanite, which has been used as a gemstone since the 1990s, can be definitively identified with a tester. However, if your piece is from an earlier era, it is highly likely to be a diamond if it passes this test.

Conclusion

While a diamond tester is a useful tool for initial identification, it is not the definitive proof of a diamond's authenticity. For more accurate and reliable results, consider using additional testing methods to ensure the stone you are dealing with is a genuine diamond.