Below is a partial list of misleading gemstone names encountered abroad, but represented as expensive gems. For explanation of how and why gems are altered see information following the below misnomers. All the chemical, physical, and optical characteristics of synthetic gemstones are identical to their natural counterparts. Good synthetics have been made since the early 1900s. Because they mimic natural stones so well, most synthetics are difficult to detect, even by experts.
Substitutes are cheaper look-alike stones.
Red spinel or garnets may be substituted for ruby, and green tourmaline is used to replace emerald. Cubic zirconia, a manmade stone from a natural substance, is a well-known substitute for diamond. Their name is often a clue to substitutions. Genuine gemstones are called by their true names, with no descriptive words as part of the name. Example, a sapphire is simply called a sapphire.