A natural gemstone is a mineral, stone, or organic matter that can be cut and polished or otherwise treated for use as jewellery or other ornament. Natural gemstones are formed in nature with no interference from humans other than being mined, cut/faceted and polished. If a stone is identified as natural, this means that it has not been treated, enhanced or altered. A gemstone has beauty, durability, and rarity.
When we talk about ‘imitation’ gemstones in the gem industry, we always distinguish between gemstones that are synthetic and those that are simulants. A simulant has an appearance similar to that of a natural gemstone, but has different optical, physical, and chemical properties.
For example, a diamond simulant describes any colourless transparent gem material which looks similar in appearance to a Diamond. In some cases, the resemblance can be very convincing, however, the optical, chemical and physical properties of diamond simulants are very different to those of natural occurring Diamonds.
Cubic Zirconia and Moissanite are lab-created materials, but a simulant may also be a natural gemstone. Natural, white Zircon was once used as a Diamond simulant; and some of the most important rubies in the world turned out to be natural Spinels. Jade (Jadeite and Nephrite) for instance, has simulants such as Aventurine Quartz, Serpentine, Chrysoprase etc.
A real gem can be deemed an imitation if it is presented as something else, usually a more expensive gem material.
A synthetic gemstone, describes gemstones that are reproduced by man in a laboratory using artificial processes. It has essentially the same appearance and optical, physical and chemical properties as the natural material.
Therefore a synthetic Diamond is a real Diamond. Synthetic Diamond, can also be referred to as laboratory-grown diamond, laboratory-created diamond, or cultured diamond. CVD diamond (chemical vapor deposition) and HPHT diamond (high-pressure high-temperature) processes are 2 of the common methods used.
Synthetic Blue Sapphires are commonly made by a method called Flame Fusion. They are made in such a way that they look like Natural gemstones. These lab created Blue Sapphires will have same chemical properties of the real stones. They will have the same hardness, density and appearance like the Natural Blue Sapphire.