How to check the authenticity of a diamond at home

Diamond jewelry is a jewelry classic. Unfortunately, the owners of such jewelry often have questions about the authenticity of the stones. For example, if a ring or earrings were given as a gift without tags. Or if you bought them yourself, but for a suspiciously low price.

Is it possible to independently check the authenticity of a diamond at home? Let’s try to understand in this material.

What a natural diamond can be confused with

There are several variants of jewelry inserts, which are often tried to pass off as a natural diamond. These include:

Fianite (zircon). An artificial stone, zirconium dioxide. It was invented by scientists from the Lebedev Physical Institute of the Academy of Sciences (FIAN) for laser equipment, but since the 90s of the XX century has gained great popularity in the jewelry industry. Visually very similar to a diamond.
Moissanite (silicon carbide). The stone is found in nature, but in the jewelry industry is used only artificially grown. Active production of moissanite began in the 80s of the XX century. The stone has a brighter luster than a diamond.
Rock crystal. Natural stone, natural silicon dioxide. Used for jewelry and arts and crafts.
Artificial diamond. A complete analog of a natural diamond from the chemical point of view, but grown in laboratory conditions.

How to determine whether a diamond in a piece of jewelry is real or fake

Rarely, when uncut stones fall into the hands of ordinary people. Most often it is a matter of checking the insert in a ring, earrings or other jewelry. There are several ways to test a stone.

Checking with water or oil

You should drop a drop of water or vegetable oil on the surface of the stone (for example, you can do this by wetting a toothpick). After that, you should try to separate the drop with a needle or toothpick.

If the drop scatters into smaller ones – with a high degree of probability, the setting is a fianite, moissanite or crystal.
If the liquid remains as a single drop – you have a diamond (natural or artificial) or a moissanite with a special diamond coating.

Breath test

The method is based on the different thermal conductivity of a diamond and its analogs. For the test it is necessary to breathe on the stone. If after several exhalations it will be covered with condensate – you are looking at a fianite, moissanite or crystal. If the surface of the stone remains dry and does not mist up – in the setting is a diamond (natural or artificial).

Please note! The thermal conductivity test is the only option you can potentially use outside of the home as well, such as at a store or pawn store to check a diamond for authenticity.

Ultraviolet testing: not too reliable

There is information that by placing a stone under an ultraviolet lamp, it is possible to determine whether you are looking at a real diamond or its analog. The first thing that is important to know is that natural diamonds can have different degrees of fluorescence: from bright to its complete absence. If you have a luminous stone in front of you, pay attention to the color of the glow: a natural diamond will more often have a blue tint, and less often it will be green or yellow. Orange-red glow is given by moissanite, other stones – gray.

Fig. 1. Different variants of natural diamonds glowing under ultraviolet light

It should be noted that luminous natural diamonds are very popular in the United States, so most of the fluorescent stones go to America. As for artificial diamonds, they usually glow under UV light, but unlike natural diamonds, they do not go out immediately, but can glow for up to a minute after the lamp is turned off.

Hardness testing: why it doesn’t work anymore

Diamonds are renowned for their hardness, so you may come across recommendations to scratch the stone with something hard (such as a diamond-tipped tool). It is indeed possible to damage a fianite in this way, but not a moissanite, as in recent years the technology of coating them with a super thin diamond film (CVD technology) has been almost universally used. As for artificial diamonds, they will pass the test as easily as their natural counterparts.

Please note! We do not recommend checking diamonds for authenticity in this way, because you may damage the stone if it turns out to be fake.