Many gemstones can now be purchased in a created or synthetic variety. The obvious benefit is a lower cost and greater clarity, although many buyers prefer the natural stones.
A synthetic gemstone, often called a "created stone", is typically perfectly uniform, clear and has absolutely no imperfections. These stones are "grown" in a laboratory, from the "seed" of a natural stone. The resulting stone is chemically identical to a naturally mined stone. Jewelry experts often compare synthetic gemstones to hybrid plants, as both are grown in completely controlled environments for optimal results.
Sapphires, ruby and emeralds are commonly sold in synthetic varieties. Because the controlled process produces flawless gems, larger created stones can be sold at a much lower price than their natural counterparts.
The easiest way to tell is a stone is synthetic is to ask the jeweler. Most reputable dealers will label their synthetic stones as "created" or will have information on the origin of the stone. If this information isn't available, examine the stone carefully under a bright light. If it is too perfect, clear or vibrant, and has a price tag much lower than similar sized stones, it's more than likely a synthetic stone.
Actively avoid stones that use the words "simulated" or "simulant". These are not synthetic, but a recreation of a gemstone using glass or extremely inexpensive crystal. They mirror the physical characteristics of a gem, but are of very low quality and are prone to shattering. Cubic zirconia is a prime example of a "simulated" diamond.
With the wide availability of these "simulated" stones, it is important to do a bit of research on the type of stone you're purchasing. Some stones, such as garnet, currently cannot be recreated in a lab, and a dealer attempting to sell a "synthetic" version of a stone that cannot be lab grown should not be trusted.
Even many mined stones that are purchased in stores are not completely natural, though. These have often gone through one or many various treatments, such as heat or irradiation, to increase the hue or vibrancy of the color. These treatments do not impact the integrity of the stone, and are permanent changes, but should be a consideration when looking for a truly natural gem.
A dealer worth doing business with will always be upfront and honest when asked whether the stone is completely natural, has been treated or is synthetic. Dealers who refuse to disclose this information may be attempting to pass the "simulated" gems as the real thing, and prey on consumers who are not able to tell the difference.
The decision to purchase a synthetic or natural stone depends completely upon your tastes, preferences and reasons for buying. If you're looking for a beautiful necklace with a large stone, a synthetic version may be your best option. The price will be lower and the stone will have a more stunning appearance than any reasonably affordable natural alternative.
If you are a collector or price isn't a consideration in your purchase, you may prefer the natural versions for their authenticity. Many buyers also prefer the naturally occurring flaws of mined stones, such as cloudiness or asymmetry, for the character and unique appearance they provide.