Cubic zirconias are not normally found in nature but they are very commonly synthesized for use as a diamond substitute. Cubic zirconias are zirconium oxide (ZrO2). This synthesized substance is very hard hard and normally colorless but can be made into an array of colors. Dont mistake this with zircon which is a zirconium silicate (ZrSiO4).
Synthetic cubic zirconias have very low costs, high durability, and looks extremely similar to real diamonds. In actuality, cubic zirconias have remained one of the most economically important diamond simulate since 1976.
Cubic zirconias are isometric, just like diamonds, which is one of the main reasons as to why they look so very similar to each other. CZ contains a precise mole percentage of metal oxide stabilizer of ten to fifteen percent.
If it didnt contain this metal oxide stabilizer then during synthesis zirconium oxide would form monoclinic crystals, which is actually its stable form in natural conditions. The physical appearance and optical properties of synthesized cubic zirconias will vary including the price.
Cubic zirconias commonly turns a yellow, greenish-yellow, or beige color when under shortwave UV. When cubic zirconias are under long wave UV the results are decreased with a whitish glow appearing. Some colored stones have a complex earth absorption spectrum.
If you add certain metal oxides into the feed powder you will get results of vibrant colors including cerium for a yellow, orange, or red, chromium for green, Neodymium for purple, erbium for pink, titanium for golden brown.
In recent years many manufacturers have tried to find a way to improve their cubic zirconias such as coating completed cubic zirconias in a light layer of diamond like carbon (DLC) such as Amorphous Diamond. The process is referred to as chemical vapor deposition.
Cubic zirconias looks so similar to a diamond that only a truly trained eye can tell the difference from the two easily.
By: Martin Mallett