Gemstones Natural vs Synthetic
What is a synthetic gemstone? A synthetic gem is created in a laboratory under controlled conditions. The gem is grown from a natural gemstone "seed". By controlling the environment in which the gem is grown, impurities and inclusions can be avoided which occur in natural gemstones. The created stones have perfect color and clarity which is so highly desired. Most natural gemstones have imperfections due to uncontrolled growing conditions in nature. Synthetic stones will have the same chemical, physical, and optical properties of their natural counterparts without the imperfections.
A good analogy for synthetic gemstone creation is growing roses. Roses grown in a hot house where their growing environment is controlled will be closer to perfection than roses that are grown in your backyard. They're both roses, but the backyard rose will most likely be flawed or imperfect due to disease, insects, and other environmental impacts. Not so with the hot house rose because of the controlled conditions.
Don't confuse simulant gemstones with synthetic gemstones. Simulants can be made up of any substance, like glass. They are made to simulate a particular gemstone, but they do not have the same chemical, physical, and optical properties of the natural gemstone like the synthetic gemstone. Some examples of simulants are cubic zirconia, moissanite, and yttrium aluminum garnet which are diamond simulants.
The most popular gemstones that synthetics have been created for are emeralds, sapphires, rubies and alexandrites. I'm sure you have seen jewelry with synthetic stones, also known as "created" gemstones in your local retail jewelry store. They are easier to obtain and less costly than natural gemstones. Synthetics have made it more affordable for people to own nice jewelry and many prefer the flawless created stones compared to the natural stones. You can usually spot a "created" stone because it's just too perfect in color and clarity. A natural stone, especially in rubies, sapphires, and emeralds, which is perfect in color and clarity, is scarce and the cost is beyond most people's means.
Should you buy a synthetic gemstone or jewelry with created stones over the natural gemstone choices? I would recommend going with your own personal preference. If you want a piece of jewelry with a flawless, perfect gem, then go with the synthetic gemstone. Also, if cost is a deciding factor. As a collector/investor my preference would be for the natural gemstone. It's value and appreciation factor will be much greater, flawed or not.
It's interesting that there are some gemstones man has not been able to synthesize in a laboratory. One example is the garnet family of gems. They have not been able to unlock garnet's secrets to create it in a lab.
How do I know if the gemstone is natural, synthetic (created), or a simulant? If you can't tell by your own examination...ask! A reputable dealer or jeweler will be honest about the origins of the stone. If they don't know or won't say, then don't buy!
Another interesting fact about gemstones that is not common knowledge to the public is that the majority of gems on the market have been treated to create or enhance their color and clarity. There are many different treatments used today. Heat treatment is the most common and widely used. I have written another article specifically regarding gemstone treatments. You can go to Gemstone Treatments to read more on the subject.
As a gemstone collector/investor, as stated before, my preference is for natural gemstones, but as an adornment in jewelry a synthetic gemstone makes for a gorgeous ring, earrings or pendant at an affordable price.