Throughout the past several decades, two man-made gemstones have been touted to be the most commonly traded diamond simulants in most parts of the world. Take note, the word simulant refers to an imitation or something that is chemically-unlike the gemstone it is imitating. Moissanite and cubic zirconia both resemble diamond to the naked eye, save for some small subtle factors, however studying gemological properties can help you separate the the two from diamond.

(Commercial testers that rely on thermal or electrical conductivity must be used with experience and caution, sometimes these do not exhibit consistency in their readings. We never use handheld or 'diy' machines as primary tests or on their own.)

Between the two imitator gems, moissanite is usually slightly more expensive. It also has some properties that even exceed those of diamond. Moissanite's 2.65 refractive index value for example, is even higher than diamond's 2.42 value. Refractive index governs the slowing and directional change of light as it enters a gemstone's more optically dense material from another material like air.

If your familiar with 'fire' the term used to describe those colourful flashes or sparks you would see while rocking or tilting a diamond, then you should know that moissanite usually showcases more of this as well. Dispersion is the proper term for this observation, and the dispersion rate of moissanite is 2.4 times higher than diamond's. Combine this with its high refractive index, and moissanite's physical appearance can look incredibly similar to diamond's in terms of light display, brilliance and beauty.



Moissanite is not as hard as diamond, but it comes close at around 9.25 on the Moh's scale. Proprietary brands and companies produce moissanite in their chemical laboratories and factories, sometimes calling it under a different trademarked name when it rolls out to retail.

Know though that moissanite is anisotropic (doubly refractive), and gemologists can easily separate it from diamond by keen observation with a gemological microscope. For us, this is a much more reliable separation test than electric conductivity (used by some diy testers), as the latter can often show mixed results due to some diamonds also having electric conductivity values close to moissanite's.

Moissanite makes for a very interesting alternative to the world's current most beloved gemstone. A lot of people here in the Philippines actually have duplicate or 'twin' versions of their jewelry made with moissanite or cubic zirconia. These are worn instead of the real thing for a sense of personal safety at times, with relation to the idea or possibility of theft. These imitations have been around for quite a long time and have since garnered a very large following in the trade. Some people purposely wear moissanite as a gem in its own right as well, due to its physical and optical traits being quite alluring to the eye.

The monetary value of moissanite however is still much lower or cheaper than even the wholesale values normally paid for either natural or lab-grown colorless diamonds.

Although the term 'fake' is widely used when pertaining to something that imitates the genuine article, a better term for these types of look-a-likes would be "simulant". Now simulant means that a stone has a different chemical composition and a different atomic structure when compared to the real thing. Glass that is cut to look like a faceted diamond, would be classified as a simulant. It is something that resembles only in outward appearance.




This is very different from the term "synthetic", which (for the gemstone industry) refers to a material that has the same essential chemical composition and atomic structure as the original, but was in fact grown artificially in a laboratory.

Diamond holds one of the highest value-per-weight materials in the world, so naturally a lot of people want to create 'fake' or faux versions of the precious gemstone.

Today let's take a look at some of the most common fakes, imitations or simulants out there on the diamond market. First up, we have the most commonly used stone; cubic zirconia. Now this refers to cubic crystalline form of zirconium dioxide.

CZ, as it's more commonly known, is the synthetic counterpart to baddeleyite, which was discovered in 1892, and is the yellowish natural form of zirconium oxide. CZ is extremely popular because its optical properties are very close to those of diamond. Although it only possesses a hardness of 8.5, cubic zirconia fashioned into round brilliant cuts, display more 'fire' than diamond, due to a higher dispersion rate. Much of the trade involving faux diamonds make use of CZ crystals for their brilliance and scintillation, echoing the 'feeling' of diamond, with much lesser costs.



Lately, several proprietary brands follow the trend of concocting their own slightly altered recipe for creating cubic zirconia. Through their efforts, they claim increases in brilliance, hardness, and other properties- however these minor trace impurities are not enough for most laboratories to change their label from cubic zirconia to something else.



Next up, we have synthetic moissanite. This material is typically more expensive than CZ, but poses a different set of difficulties when separation from diamond is needed. Standard pen-hold thermal detectors (diamond detector machines), will often label moissanite as diamond, due to their very close thermal conductivity ratings. Dual or electronic conductivity testers may have a better chance at detection, but we've often seen these machines misread stones as well. Moissanite however, is a doubly refractive stone, and splits light rays that pass through its material, unlike diamond which is singly refractive. Moissanite also displays a lot more fire (dispersion than diamond), as pictured below.



After CZ and moissanite, secondary imitators of diamond are glass, white sapphire (natural or synthetic), rock crystal quartz, and synthetic colorless garnets like gadolinium galium garnet and yttrium aluminum garnet. These stones also have appearance similarities to diamond, but not as much as the previously mentioned high rankers. Their gemological properties allow gemologists to properly separate them from diamond as totally different species of gemstones.