Artificial Stones: They are gems that do not have a correspondent in Nature. Laboratory products totally invented and created with the sole purpose of  imitating natural gems of greater value, the most widespread example is  Cubic Zirconia , which many call simply (erroneously) ) Zirconia or Zircon.  Artificial stone that imitates the Brilliant cut Diamond.

Lab made gemstones have exact correspondence in Nature, have the same Chemistry, Crystal structure and equal Hardness to the corresponding Natural. In the following years other people with the same procedure were able to synthesize also: man made sapphire, colourless Corundum and other colors, lab ruby and Sapphires Asteria, etc .; the list is very long and to date the attempts and laboratory researches have not stopped, in an attempt to synthesize even the most complex gems.

 They insert the same chemical elements of a particular gem into some sophisticated equipment and reproduce (as much as possible) the same temperatures and pressures that normally occur in nature. There are today various methods to Synthesize Gems, some of which do not only reproduce the Color, Chemistry and Crystalline but they also try to imitate the characteristic signs that initially tended to distinguish syntheses from Natural gems.

The emergence of these synthesis methods led in the following years to other evolution, such as: treatments, heating, irradiation etc., this gave the possibility of obtaining Synthetic Gems retracted further to create internal inclusions similar to those of Natural Gems,  with the aim of getting as close as possible to the aesthetic aspect of Natural gems.

Most important artificial stones:

As you can imagine, the more the Natural Gem has value and demand on the market, the greater will be its Imitations, it is surely the case of the Diamonds considered the King among the precious gems. As already mentioned, the main Imitations of the known Diamonds are: Lead glass, GGG, Lithium Niobate, Strontium TiTanate (Fabulite, Diagem), YAG, Cubic Zirconia ( Dievalite, Phianite, Fianite) commonly ( erroneously) called Zircon , Synthetic Moissanite, Synthetic Diamond.

 In most cases you are talking about artificial gems whose appearance imitates diamonds, but hardly equal or equal in splendor and beauty, while in other cases, you can get as close as possible, like with synthetic Moissanite and synthetic diamonds , having now reached excellent levels.
Let's talk about the 2 most used and widespread Artificial stones in the jewelery and Bijoux , Strass and cubic Zirconia.

Cubic Zirconia ("Zircon"): This Artificial stone is certainly the best ever among the "poor" imitations of Diamonds, the cubic Zirconia , widespread on the market today, is erroneously called Zircon , this terminology is now widespread and affirmed, being normally used by everyone, including employees of the sector. Especially the Gemmologists (but not only), try to maintain the correct terminology, as there really is a Natural Gem with the name Zircon , which has nothing to do with loose cubic zirconia, a different Chemical, Crystalline and Hardness structure.

Strass: It is an artificial product created by man, a lead glass, those that many would define as a simple crystal with a high lead content to increase brightness and "resistance", a simple cut is applied to this crystal as standard with some veneers, and the lower part (pavilion) is covered with materials to increase the brightness.