First, we use many of the terms that were taught to our gemologists at their alma matter (GIA). Such terms include the differentiation between the words "Syntheic" and "Simulant". So a synthetic gem refers to a man-made, artificially-grown or laboratory-grown version of a gemstone that still holds the same essential chemical composition and crystal structure.
The word simulant however, synonymous with certain other words- "imitation or faux", refers to a material that merely looks like another gem that it is trying to copy visually. It does not share the same essential chemical properties as that other gemstone at all.
Some people prefer not to use the word synthetic, as it can come off as negative. In an objective look, man-made gemstones are not negative at all. People refer to these items as 'fakes', but it really depends on individual opinion. If it has the same chemistry on an atomic level- would you still consider something as a fake version of something else? The people that do, often cite that these man-made gemstones do not hold the same monetary value or weight-of-value as their natural counterparts. This much we've observed to be true- by mere comparisons done on the pricing rates of hundreds of exhibitors and sellers that participate during the international gem and jewelry trade shows (HK).
High quality synthetic rubies for example, although strikingly beautiful, as durable and as hard as natural rubies, can be bought for five to twenty dollars per carat regularly on most markets. An equivalent ruby (fine quality) could command up to tens of thousands of dollars per carat. Here lies the main reason why many man-made gems are still being called fakes today- the difference in what people are willing to pay for them.
Note also that many traders may use the brand names of crystal-growing companies instead of the word "synthetic" or "lab-grown". If you're not familiar with a certain word, always ask the seller to explain what they mean by it. "Chatham" and "Tairus" for example are two companies famous in the lab-grown gem manufacturing businesses, so you may see label cards saying "Chatham emeralds" or "Tairus emeralds" at jewelry bazaars or trade fairs- even if the sellers aren't exactly those companies. By these terms, they simply mean that their items are laboratory-grown at the very least (or they could have purchased them from those suppliers).
These two words sound very similar admittedly- synthetic and simulant. Maybe because of this, a lot of jewelry buyers often think of them as synonymous to each other, when in fact- they are not.
Additionally, just because a material is a simulant of a material, does not automatically mean it is man-made. Let's say for example, we look at a faceted clear-quartz stone. The quartz was cut in a round brilliant style to "imitate" diamond. It is therefore considered as a diamond simulant, but it is still also a natural quartz stone- not a synthetic gemstone at all.
Tsavorite is an expensive natural green garnet, and is a natural precious gemstone in its own right, but some people still use it for the purpose of imitating very high clarity emeralds (due to its tendency for better transparencies). In this case, the stone can be considered as a simulant as well. This does not in any way though detract from its original value as a tsavorite gemstone whatsoever.
This is just a discussion on labels and words though. Everyone of course will still have their own definition of what is real or what is fake, we are not here for debate, but to merely express how we define certain terms, and how the trade is often divided when speaking about other labels and wordings.
Some simpler terminologies that are sometimes confused have to do with diamonds and gold. The word "Carat" is very different from the word "Karat". The first refers to a diamond's weight. One carat is equal to about 1/5th of a gram. This is often used as an introductory term to estimate a diamond's size as well, for stones that are cut properly.
The word "Karat" on the other hand refer strictly to gold purity. Gold purity is expressed as a ratio or fraction of wholeness. 24 karat gold is pure gold, while 18 karat gold means that an item is 18/24 in gold purity. A 14 karat gold item is 14/25 in gold purity. In many countries there is debate amongst traders regarding what constitutes the minimum purity for gold jewelry to be considered as high-end. In the U.S., we believe that many people still consider 10 karat gold to be appropriate for gold jewelry. In countries like Italy on the other hand, when you say gold jewelry, the reference is usually meant for 18 karat gold items.
Wordings and phrases can also be confusing when used to describe gemstone treatments. "Heating" for example, is a word often used to refer to the typical enhancement used for rubies and sapphires. Today, a majority (Over 90%) of rubies and sapphires undergo some sort of heating procedure in order to enhance their color and sometimes clarity. The problem is that "heating" as a word is sometimes used by shady vendors who try to sell other types of enhanced products like lattice diffuesd gemstones. These gems are also enhanced with heat, but powdered chemicals are added into them, in order to drastically change the color of the original material.
The term "Heating" or "Heated" should only be used to describe gems that have undergone purely temperature based enhancement procedures only, without the addition of chemical components like flux-catalysts or chemical dopants.
Lastly, the jewelry buying community here in the Philippines especially, sometimes has trouble with understanding the definition of the term "Cultured" in reference to pearls. Some people think that if you say "cultured", it means fake. The fact of the matter is that more than 99% of pearls used today in the trade are indeed cultured pearls, and that is completely accepted even in fine market tiers. Cultured pearls come from mollusks as well, as they are grown in the sea or in riverbeds and lakes. Pearl farmers add a shell-bead nucleus or a piece of mantle tissue into a mollusk's interior artificially, and the animal will slowly coat it with organic nacre over the years. Each layer added by the animal is exactly the same material as what you would find on a wild-caught pearl.
Cultured pearls were invented to meet the demand that wild-caught pearls couldn't fill even a hundred years ago. They made it possible for spherical or round pearls to be supplied in dependable qualities all around the world. The very finest examples of cultured pearl strands can cost 500,000 USD or more in fact.
