Synthetic stones and simulants

A synthetic gemstone is a lab-created material, which has the same appearance and chemical, physical, and optical properties as the natural one. A simulant has an appearance similar to that of a natural gemstone but has different properties. It is possible for a stone to be both synthetic and a simulant. It is important to know that the simulant may also be a natural gemstone. Some of the most popular rubies turned out to be natural spinels.

There is a large industry producing synthetic quartz using a hydrothermal synthesis. See the samples above.

The so-called cubic zirconia, S-007, is a lab-created material, cubic crystalline form of zirconium dioxide, and example of well-known diamond simulant.