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How to tell moissanite from diamond? Most comprehensive ways

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The fire color of diamond is cold, mainly blue, while the fire color of Moissanite is warm, mainly orange and red. In contrast, the fire color of Moissanite is significantly higher than that of diamond. The refractive index and dispersion value are different: the refractive index of a Moissanite diamond is 2.65, and the color dispersion value is 0.104; The refractive index of natural diamond is 2.417, and the color dispersion value is 0.044.

How to tell moissanite from diamond?

One of the easiest ways to identify moissanite and diamond is:

1. Moissanite Tester

The best way to tell whether a stone is a diamond or moissanite is to use a diamond tester or a moissanite tester. They are now making Moissanites which have very low electrical conductivity and register “Diamond” on most testers, including this Moissanite tester.

tester test moissanite

2. Preliminary color identification.

3. Fluorescence testing.

4. Use a thermal conductivity meter.

5. Another method is to use a magnifying glass to observe the refractive index of minerals.

6. Use the hardness test to distinguish diamond and Moissanite.

show moissanite cutting

The specific analysis is as follows:

1. Color identification:

Although diamond can appear in various colors, they are usually transparent or white. Moissanite stone can be dark, light, or transparent. Therefore, by observing the color, the two can also be distinguished.

2. Fluorescence test:

Many diamonds will emit fluorescence under ultraviolet light, while Moissanite stone will not. You can use a UV light to test gemstones.

3. Use of thermal conductivity meter:

This instrument can test the thermal conductivity of minerals, and diamonds have very high thermal conductivity, while Moissanite has low thermal conductivity.

4. Refractive index:

Real diamond has a high refractive index, while synthetic moissanite has a low refractive index. You can place minerals above the text and observe their shape and deformation of the text to determine the refractive index. Observe the boundary between the bottom of the mineral and the object through a magnifying glass and note whether the boundary is distorted or deformed. The difference in refractive index between minerals and the surrounding environment causes this deformation. Diamonds have a higher refractive index than air, resulting in significant deformation. In contrast, Moissanite stone has a lower refractive index and less deformation.

5. Hardness test:

Diamonds are the hardest substance in the world, with a Mohs hardness level of 10. In contrast, the Mohs scale hardness of Moissanite is only 6 to 7. When testing, you need to use diamond or other substances with a higher hardness to scrape minerals. If a mineral is scratched, its hardness is lower than the substance that scrapes it. Since diamond is one of the hardest materials in the world, only other diamonds or materials with very high hardness can scratch it, so a hardness test can be used to distinguish diamond from Moissanite. However, it should be noted that using hardness testing instruments requires certain skills and experience to avoid damage to minerals.

diamond vs moissanite

The difference between a Moissanite and a diamond

While moissanite has a very similar appearance to diamonds, they have many key differences. Let’s look as follows:


The colors of diamonds are generally divided into colorless – light yellow (brown, gray) series and colored series.

The color of natural Moissanite mainly presents dark green and black, and the common colorless or slightly yellow and light green Moissanite on the market is primarily synthetic. But Most of the moissanite on the market today has been enhanced to be colorless or as close to colorless as possible.


Moissanite stones and diamonds are fundamentally different in composition. Diamonds are pure natural gemstones, mainly composed of carbon, with a carbon content generally above 96%. The other impurities are mostly Si, Al, Ca, Mg, Mn, Ti, Cr, N, etc. Moissanite diamond is called “synthetic silicon carbide”; more specifically, it should be called Moissanite stone. Natural Moissanite is extremely rare, and its particles are very small, so laboratory synthesis is used in the market. Obviously, Natural diamonds are worth more.

But many jewelers consider moissanite a diamond alternative, not an imitation, though you will find plenty of that language on the internet.


The Mohs scale hardness of diamonds is 10, while Moissanite is 9.25; in contrast, the hardness of Moissanite is lower than that of diamond.

Unlike other forms of diamond, moissanite never loses its sparkle or brilliance over time due to its hardness and refractive index that tests the best among all diamonds on the market!


Moissanite has the characteristics of a high refractive index and high dispersion, making it more sparkle and stronger fire than diamonds. Many people will find Moissanite more attractive. You’ll notice that moissanite and diamonds have different brilliance.

moissanitefire vs diamond fire


The specific gravity of diamond is 3.52, while moissanite is 3.22.

Note: A specific gravity solution can quickly distinguish unembedded bare gem stones.


Diamond and moissanite stone have different densities. Natural diamond is heavier than Moissanite. What this means is that if you compare the weight of a moissanite and diamond of the same size, the moissanite will be lighter.

Magnify and observe

The interior of nature diamond usually contains mineral inclusions, growth structures, etc. After cutting and grinding, they are “flat and straight” with sharp edges.

The best way to observe this effect is to view the gemstone at an angle from the crown (bezel) facet.

When Moissanite is magnified to observe the standard linear inclusions, birefringence (back facet edge ghosting) is obvious. The test should be repeated again by varying the angle of tilt and observation of the culet through the crown facets.


Diamonds are homogeneous and exhibit an utterly dark phenomenon under a polarizer. While moissanite is a heterogeneous body showing a “four bright and four dark” phenomenon under a polarizing microscope. To confirm the test, you should tilt the diamond and try to inspect the stone from another angle.


The dispersion value of diamonds is 0.044. while moissanite is 0.104. While diamonds are the most popular choice for engagement ring, some prefer the fire and brilliance of moissanite.

Note: The fire color of diamonds is cold, mainly blue, while the fire color of Moissanite is warm, mainly orange and red. In contrast, the fire color of Moissanite is significantly higher than that of diamonds.


Synthetic moissanite is conductive. Diamonds are mostly good insulators; the purer the diamond, the better its insulation. Type IIa diamond has the best insulation, while Type IIb diamond can conduct electricity due to their presence of trace elements.

Polishing pattern

Cutting is also one of the 4c standards for considering the value of diamond.

Diamond: Due to their high hardness, constantly adjusting and switching angles and directions during polishing is necessary. The vast majority of diamonds do not have a polished waist and retain a rough surface, with few phenomena such as “non-sharp points,” “uneven points,” and “polishing lines”;

Moissanite: due to its small hardness and low price, it is not polished well or polished in the same direction during processing, and the contrast between adjacent facets is obvious.

Constituent elements

Diamonds are made of carbon element C, while moissanites are made of silicon carbide SiC, which cannot be distinguished from the outside or with a moissanite tester

Refractive index

When observe with a 10x magnifying glass, the diamond, due to its high hardness, will have highly smooth facets after grinding, and the sharp edges between the facets will be very sharp. Although ordinary Moissanite is also high in hardness, its facets and edges are not as sharp as diamonds. However, Belgian magic star diamond use special cutting techniques, and when zoomed in, the sharp edges between the facets are also very sharp, which is not much different from diamond.

Inclusion body

Under a magnifying glass, the inclusions in diamonds are mostly cloud-like or point-like and rarely needle-like. The inclusions in moissanites are mostly columnar and sheet-like.


Diamond include natural diamond and lab diamond. Natural diamonds are natural gemstones formed by the precipitation of carbon elements under particular high temperatures and pressures over the years. Lab diamonds are artificially cultivated quickly by simulating the formation environment of diamonds. Still, their main element is carbon C, And the Moissanite diamond is only artificially synthesized, consisting of silicon carbide SiC. It is difficult for ordinary people to distinguish between natural, lab, or moissanite, which are used as bare stones for jewelry after polishing.

In terms of value and purpose (Price)

Natural diamonds are expensive and rare, so they have been used for years to set valuable jewelry. Lab diamonds are less valuable than natural diamonds, so most are used in industrial fields, such as cutting tools. The other part is used to replace real diamond jewelry inlay. Moissanite diamond silicon carbide has been used in electronics for years, such as light-emitting diode materials. With the continuous improvement of people’s technology for synthesizing Moissante diamond and the increasing quality of their colors, it began to enter the jewelry field and gradually appeared in people’s eyes and became well-known.

Moissanite has been marketed as a low-cost option for a diamond engagement ring due to its appearance and diamond-like properties in clarity & hardness. So when you buy a engagement ring to consider use moissanite gem as center stone also a nice choise

moissanite vs diamond price


Diamond above 0.5ct have authoritative appraisal certificates, and national and international certificates can effectively judge the authenticity of diamonds. You can check the authentication certificate if you are unsure whether you are buying diamond or moissanite stone. It is reported that the GIA Gemology Institute of the United States can issue a certificate for Moissanite, but it indicates that it is Moissanite, not diamond. In addition, some national inspection departments can also identify Moissanite but will mark it as synthetic carborundum.

In fact, for most consumers, there is no significant difference between Moissanite and diamond. Consumers are advised to choose a trustworthy business to avoid buying Moissanite as a fake diamond. Don’t forget to ask for the authentication certificate issued by the authoritative department. If you are shopping for a diamond ring, make sure you only buy GIA or AGS graded diamonds from reliable jewelers.

 Diamond testers offer a quick and easy way for laypeople to test their diamond jewelry for authenticity.

gia certification

People may also want to know these questions

How to tell moissanite from cz?

Moissanite and cubic zirconia (CZ) are diamond simulants, meaning they are artificial materials designed to look like diamonds. While they may look similar at first glance, there are some differences between the two that can help you distinguish them.

Here are some ways to tell moissanite from CZ:

Hardness: Moissanite is a naturally occurring mineral with a hardness of 9.25 on the Mohs scale, making it one of the hardest materials on Earth. Conversely, CZ has a hardness of 8-8.5 on the Mohs scale, making it less scratch-resistant than moissanite. You can use a diamond tester or a scratch test to determine the hardness of a stone.

Brilliance: Both moissanite and CZ have high brilliance and sparkle, but moissanite has a higher refractive index than CZ, which can create more fire and rainbow flashes. You can observe the sparkle and rainbow flashes by tilting the stone under the light.

Color: Moissanite has a higher color dispersion than CZ, which means it can create more color flashes. CZ, on the other hand, tends to have a more uniform color appearance. You can observe the color flashes by examining the stone under different lighting conditions.

Price: Moissanite is generally more expensive than CZ due to its rarity and its natural properties. If a stone is sold at significantly lower than the market value for moissanite, it is likely to be a CZ.

While moissanite and CZ may look similar, some differences in their properties can help you tell them apart. If you are still unsure, it is best to consult with a professional gemologist or jeweler who can help you identify the stone.

How to spot fake moissanite?

The simplest method is to use a thermal conductivity tester to test the stone’s thermal conductivity. Genuine moissanite has a very high thermal conductivity, while synthetic stones have a lower thermal conductivity. If you don’t have access to a tester, consider testing the stone at a jewelry store or laboratory. Additionally, you can purchase moissanite from reputable brands and dealers to reduce the risk of buying a fake.

How to test if moissanite is real?

There are several ways to test if moissanite is real:

Thermal conductivity test: This is one of the most reliable tests for determining whether a stone is a genuine moissanite. Moissanite has a very high thermal conductivity, so it conducts heat well. A thermal conductivity tester can measure the heat conductivity of the stone and determine if it is genuine.

Visual inspection: Genuine moissanite is usually straightforward and free of inclusions or blemishes. However, slight inclusions are possible, so this method is not foolproof.

Refractive index test: Moissanite has a higher refractive index than most other gemstones, which means it bends light more than other stones. You can use a refractometer to measure the stone’s refractive index and compare it to the known refractive index of moissanite.

Weight: Moissanite is slightly lighter than diamonds so you can compare the weight of the stone to a diamond of the same size. If the stone is significantly heavier than a diamond of the same size, it may be a fake.

Electrical conductivity: Moissanite has a higher electrical conductivity than diamonds or other gemstones. This means it conducts electricity better. You can use an electrical conductivity meter to test the stone and determine if it is genuine.

It is best to have a professional gemologist or jeweler perform these tests to ensure accurate results.

Is cubic zirconia a fake diamond?

Cubic zirconia (CZ) is a synthetic gemstone often used as a diamond simulant. CZ is not a real diamond but is designed to look like one. CZ is made from zirconium oxide and is synthesized in a laboratory. It is less expensive than natural diamonds and can be produced in various colors. It is often used as a diamond simulant or imitation diamond. 

CZ is durable and can withstand everyday wear, but it is not as hard as a real diamond and can become scratched over time. CZ also has a different refractive index than a diamond, meaning it does not sparkle as much as a diamond.

Is cubic zirconia good quality?

The quality of cubic zirconia (CZ) can vary depending on the manufacturer and the material used. However, CZ is considered a good quality, affordable, and widely available gemstone.

CZ is designed to mimic the appearance of a diamond, and it can look very similar to a high-quality diamond. It is colorless, transparent, and has good clarity, all desirable traits in a diamond or diamond alternative. CZ can also be cut to precise shapes and sizes, which makes it easy to incorporate into jewelry designs.

However, it is essential to note that CZ is not as durable as diamond and can become scratched or damaged more easily. CZ is also not as valuable as diamonds and does not have the same investment potential as natural diamonds. CZ can be a good option for those looking for an affordable and visually appealing diamond alternative.

Is moissanite a lab-grown diamond?

No, moissanite is not a lab-grown diamond. Moissanite is a naturally occurring mineral discovered in a meteorite in 1893 by a French scientist named Henri Moissan. While moissanite can be found in nature, it is scarce, and the vast majority of moissanite available in the market today is made in a laboratory setting. This lab-created moissanite has the same chemical and physical properties as natural moissanite, and it is considered a high-quality and durable alternative to diamonds.

On the other hand, lab-grown diamonds are created using a different process called high-pressure, high-temperature (HPHT), or CVD. Lab-grown diamonds are made of the same material as natural diamonds – pure carbon – and have the same physical, chemical, and optical properties as natural diamonds.

While moissanite and diamonds may look similar, they are not the same material and have different optical and physical properties. Moissanite has a higher refractive index and dispersion than diamond, reflecting light and sparkles more than diamond. Additionally, moissanite is more durable than many other gemstones, including diamond, making it a popular choice for engagement rings and other fine jewelry.

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