This article describes the differences between natural diamonds, cubic zirconia, and cultured diamonds.
|Natural Diamond||Cultured Diamond||Cubic Zirconia|
|Price (1 carat, cut, yellow)||$20,000||$4,000||< $20|
|Hardness (Mohs scale)||10||10||8.5|
|Index of Refraction||2.42||2.42||2.17|
|Main Chemical Component||Carbon||Carbon||Zirconium Oxide|
|Production Cost (est.)||$1000s?||$100s||$1s|
Diamond, also known as adamant, is a naturally occurring carbon allotrope. In other words, it is composed of carbon atoms arranged in a particular structure. The material is the hardest known to be found in nature. Natural diamonds are produced from mines.
"Cultured" diamonds are a type of man-made diamond. While synthetic diamonds have been produced for decades, they have been small and limited to industrial uses. Cultured diamonds, on the other hand, can be up to 2 carats and come in a variety of colors such as clear, yellow, orange, and pink, making them suitable for jewelry. Cultured diamonds are produced using a newly invented production method that grows the crystals from a seed under high pressure and temperature. Two companies, Gemesis and Apollo Diamond, are competitively developing the manufacturing processes.
As the above table shows, the resulting diamond is identical in all ways to natural diamonds. Natural diamonds almost always have structural irregularities or chemical impurities. With cultured diamonds, such imperfections must be added to simulate nature and produce colored diamonds. Whereas colored diamonds (such as Jennefier Lopez's pink diamond engagement ring) are extremely rare in nature, they are cheaper to synthesize because they take several days to grow versus several weeks for clear diamonds. This may change as the manufacturing processes are perfected.
Unlike cultured diamonds, cubic zirconia (abbreviated CZ) is made of a different material than natural diamonds. It primarily consists of zirconium dioxide. Therefore, its chemical properties are close, but different from diamonds. While cubic zirconia has more 'fire' or light dispersion, it is heavier and less hard. In absolute terms, diamonds and cultured diamonds are about 500 times harder than cubic zirconia.
There are various claims about whether or not cubic zirconia can be differentiated from natural diamonds by the untrained, unaided eye. However, simple lab tests can easily differentiate them since they are made of different materials. On the other hand, there is no way to differentiate between a natural diamond and a cultured diamond. This fact causes great consternation to the diamond industry, which is racing to develop differentiating methods.
In order to avoid confusion and increase legitimacy, the companies producing the cultured diamonds are taking measures to mark their diamonds. For example, they might laser inscribe them or add trace impurities. Otherwise, diamond buyers would not be able to tell if the diamond they are buying originated from a natural mine or from a machine. A natural diamond might command a premium due to its ostensible rarity and the expense of mining it. An unscrupulous seller might pass off a far less expensive cultured diamond as a real diamond. Whatever risk the buyers perceived would directly translate into lower prices for real diamonds. Some buyers may not even care about the origin.
Diamonds are many things to many people. They are desired as objects that represent status, wealth, love, divinity, and purity. If pure diamond can be manufactured at a low cost, then the symbolic value may or may not change. What is certain, though, is that there would be economic benefits to society. The properties of diamonds, particularly hardness and thermal transmissivity, can be used in many applications, including semiconductors. Personally, I wear eyeglasses and I would pay a premium for eyeglass lenses made of diamond. Instead of being only scratch-resistant, they would be completely scratch-proof!
The articles in Wikipedia are required reading for anyone wanting more details on diamonds, cultured diamonds, and cubic zirconia.