Last updated on April 9, 2021
People often look for diamond simulants instead of real ones for a variety of reasons. However, the main motivation is their affordable price compared with natural diamonds. So let’s take a look and find out if it is worth buying imitations and which of them are the best diamond simulants.
What Are Diamond Simulants?
A diamond simulant, also known as simulated diamond, diamond imitation, imitation diamond and diamond alternative, is a stone with gemological characteristics similar to those of a real diamond.
As the name suggests, diamond simulants are used in jewellery production to imitate real diamonds. While they look similar to the real thing, diamond imitations always have a different chemical structure and physical properties from those of a diamond. A trained gemologist with the appropriate equipment will always be able to tell a diamond simulant from a real diamond, even by visual inspection.
Diamond simulants can be both natural and synthetic. Among the most popular synthetic simulants are rhinestone, cubic zirconia (CZ), moissanite, white sapphire, spinel, rutile, strontium titanate, YAG (yttrium aluminium garnet) and GGG (gadolinium gallium garnet). Natural diamond alternatives include quartz, zircon and topaz.
It is important to note that lab-grown diamonds, also known as synthetic, man-made, cultured or cultivated diamonds, are not diamond simulants. They have the same crystal structure and chemical composition (100% carbon) as natural/mined diamonds.
Moreover, synthetic diamonds have the same physical and optical properties as natural stones, meaning they have the same hardness (10 on the Mohs scale) and refractive index (2.417 – 2.419). The only difference between lab-grown and natural diamonds is that lab-grown diamonds are created synthetically in laboratories, while natural ones are mined from the earth.
What Are the Best Diamond Simulants?
The best diamond simulants are those that closely approach the real thing. They should be similar in terms of both physical properties and overall appearance. Moreover, the best diamond simulants should be nearly as hard as real ones to be cut in the same fashion and to create a similar fire, brilliance and scintillation.
Considering the above-mentioned determinants, the best stones that are very similar to real diamonds are moissanite, white sapphire and cubic zirconia.
Moissanite is a popular gemstone in its own right; however, it is also one of the best diamond imitations and for a good reason. Moissanite is one of the hardest substances on earth, with a score of 9.25 on the Mohs scale, while diamond’s hardness is 10. This makes it highly scratch-resistant and suitable for everyday wear.
Although moissanites and diamonds can look similar when viewed from a distance, there are major differences between them.
The moissanite colour scale is similar to the GIA colour grading scale; however, it is not an official grade but a term used to describe a stone’s colour. All moissanites available on the market are coloured in some way. Moissanite is different from diamond in composition, meaning it displays colour differently. Even if graded as “colourless”, moissanites will still project yellow, green or grey hue in certain lights. The larger the stone, the more noticeable the tint.
Like diamonds, moissanites often come with imperfections visible when they are viewed under magnification. Since all moissanites sold on the market today are synthetic they rarely come with a clarity grade below VS level, meaning their clarity is higher than that of average diamonds. Although moissanites are graded for clarity using the GIA clarity scale, it is important to mention that the Gemological Institute of America does not grade diamond simulants. This means the certificate will be given by the manufacturer or seller of the stone.
The brilliance of moissanites and diamonds is different. Moissanite has a refractive index from 2.65 to 2.69, which is higher than that of a diamond. The rainbow flashes emitted by moissanites are beloved by many people, but others feel that moissanite’s colourful and intense brilliance is too much, especially in sunlight.
White sapphire is another gemstone often used as a diamond simulant, as its appearance is quite similar to that of a real diamond.
Sapphire is a precious gemstone and the second naturally occurring hardest material in the world, with a score of 9 on the Mohs scale. It is worth mentioning that, unlike moissanite, white sapphire is a natural gemstone that makes it a great option for those looking for a natural diamond alternative rather than a cultured lab-grown stone. However, there are also synthetic sapphires used as a diamond alternative.
From the colour and cut quality perspective, white sapphires offer an almost identical look to traditional diamonds. Although white sapphires occur in nature, in most cases, they are yellow or grey stones that have been heat-treated or chemically treated to achieve a colourless look.
The disadvantage of white sapphires is the way they refract light. The first thing one notices when comparing a white sapphire with a real diamond is the difference in their brilliance and sparkle. White sapphires tend to appear somewhat cloudy and milky inside and have a lower refractive index of 1.76 – 1.77, meaning they can not compete with diamonds in shine.
Cubic zirconia, also known as CZ, is one of the most widely used stones to imitate a real diamond. The reason for its popularity is the affordable price, which is only a fraction of what a real diamond costs.
Like moissanite, cubic zirconia has a synthetic origin; however, it is not among the hardest diamond imitations. It has an 8.25 – 8.50 rating out of 10 on the Mohs scale. Compared with moissanites and white sapphires, cubic zirconia tends to scratch more easily, and when it has too many scratches on the surface, it loses its original brilliance.
Since cubic zirconia crystals are created in labs, they are usually internally flawless. This makes them very attractive to many buyers around the world. However, this is also one of the main ways to tell CZ and diamond apart as no diamond is perfect.
Cubic zirconia has a much lower refractive index (2.17) than a diamond (2.417 – 2.419). This means when cut and polished, it does not show true brilliance and fire because light passes through CZ much differently. It has higher dispersion (0.058-0.066) than a diamond (0.044), and for this reason, when exposed to light, CZ exhibits flashes that are more colourful than those of real diamonds.