Diamond simulant engagement rings have imitations of diamonds' appearance, or “fake diamonds”, but they do not have the same physical or chemical characteristics. Unlike the artificial diamonds that are actual diamonds created in a laboratory, the simulant is a stone that is substituted for diamonds.
The most popular diamond simulant engagement rings are made using the cubic zirconia and the synthetic moissanite.
Cubic Zirconia (CZ)
It's the cheapest, most commonly encountered diamond simulant. It is obtained in laboratories but it can also be found in nature (the natural stone is Zircon) and has the following properties:
- is colorless — color can be induced
- has quite good resemblance to diamonds in sparkle and fire, although comparing the two stones side by side, CZ has less brilliance (intensity) than diamond
- has a refractive index of 2.15, while diamond's refractive index is of 2.42, therefore diamonds are brighter than CZ
- has lower thermal conductivity than a diamond — that is why it can be easily identified with a thermal pen tester.
- is less hard than diamond (8½ for CZ vs. 10 for diamond on the Mohs hardness scale), so it does wear and scratch in time (but most precious gems do)
- has greater density than diamond, therefore one piece of CZ will weigh more than a piece of diamond the same size.
- can go dull and cloudy if it is of inferior quality and if exposed to strong sunlight for long periods.
Synthetic Moissanite
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Is a diamond simulant recently introduced on the market and has properties much closer, almost similar to those of diamonds, so close that, unless expert laboratory analysis is made, it can be taken for a diamond. It is more expensive than CZ.
Natural moissanite was discovered in a meteorite, therefore it is not largely available. It was identified by Dr. Henry Moissan, in Arizona, in 1893. Its chemical composition is “silicon carbide”.
Moissanite's Properties
- contains slight tints of gray, green, yellow
- has quite good resemblance to diamonds in sparkle and fire; when comparing the two stones side by side, moissanite has more brilliance and fire than diamond
- has similar thermal conductivity with a diamond — it cannot be easily identified with a thermal pen tester
- has a refractive index of 2.65, while diamond's refractive index is of 2.42, therefore moissanite is brighter than diamonds. Moissanite's specific feature is that it has double refractivity(whereas diamonds are “singularly refractive”), thus it is easy distinguishable from a diamond when testing refractivity.Using magnification and looking from a side, not exactly from the top, two facet lines can be noticed instead of one - this is an optical effect due to the way the light is refracted
- is less hard than diamond (9,25 for moissanite vs. 10 for diamond on the Mohs hardness scale)
- has smaller density than diamond, therefore one piece of moissanite will weigh less than a piece of diamond the same size
- is more resistant to heat than a diamond
Roughly calculated, taking into consideration stones of the same dimensions, the price of CZ is around 1% of the cost of a diamond and that of moissanite is around 10%. Of course there are variations depending on the source.
Diamond simulant engagement rings may be a cheaper alternative but they do reveal their real nature at analysis. Nevertheless, simulants can be successfully used as side stones or baguettes — especially moissanite — due to the fact that smaller diamonds often tend to be low in clarity, so this replacement would result in a plus for the final effect. Cubic Zirconia are not advisable to be mounted together with diamonds, as they do not stand comparison — they become very noticeable.
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