The origins of the names of the main gemstones, which are still widely used today, date back to ancient times, and since they were used long before the mineralogical sciences were separated into a separate branch, mineralogy, the meanings of these names differed from time to time. If jewelers had used names taken from mineralogy, there would have been no confusion or uncertainty, but it should be borne in mind that many of these names are unknown or at least unusual to people who are not involved in this science, and that, in general, it is undesirable to completely abandon the names that arose in ancient times. Of course, the name chosen for the first time found stone may have a very large impact on its future fate. The attractive red stone that accompanies the diamond in South Africa, under its own name "pomegranate" was hardly in demand, but it became popular under the wrong name "Kapese ruby". For the same reasons, it was considered appropriate to propose the name "chrysolite" to denote the shiny green pomegranate found in the Urals; this name was extremely unsuccessful because the term is constantly used in mineralogy to denote the stone known in jewelry as "peridot".
The names commonly used in jewelry were given to gemstones mainly by their color, the most obvious but least reliable physical characteristic of the gemstones. In order to separate the stones with clearly different hardness, special epithets were introduced. Thus, the term "Oriental" began to be used to denote varieties of corundum close to the hardness of the diamond, not because the corundum was brought from the East, but because at that time the best gemstones came to Europe from there. Similarly, due to the fact that many valuable samples of real topaz were brought from Brazil, the epithet "Brazilian" began to be used to distinguish this type of stone from yellow quartz.
Almost all red stones were united under the name of "ruby" or arbitrary names of "rubellite" and "rubicelle". The term "ruby" should be used only in relation to precious red varieties of corundum.
The name "sapphire" always means blue stone. Initially, it was apparently used to denote lapis-lazuli and similar minerals, and then, when the precious blue variety of corundum was discovered, it was this magnificent stone that began to be called. Mineralogists in the past used the name in a broader sense: to denote all varieties of precious corundum, including rubies. Modern jewelers use it in the same sense, but exclude rubies; for example, they speak of white, yellow, green and even pink sapphires.
Yellow stones, as a rule, were united under the name "topaz". Actually, the topaz is a solid natural fluorosilicate of aluminum, which is colorless in its purest form, but pleases the eye with a wide palette of shades resulting from the presence of metal oxides; however, jewelers have long used this term to denote a yellow variety of quartz - citrine, however, when talking about the actual topaz, the word "Brazilian" was added. Oriental topaz, royal topaz, and Indian topaz are all yellow corundum, while western topaz is yellow quartz (citrine).
The name "emerald" has always been used to denote green stones. Initially, this was the name given to the chrysocolla, an opaque greenish stone, and later the name was used to denote the priceless variety of beryl in herbaceous green, for which it is still used to this day. Eastern emerald is green corundum. In the 18th century, green tourmaline was usually called the Brazilian emerald. The name "Ural emerald" was tried to be used to denote a green pomegranate from the Ural Mountains.
Amethyst is beautiful violet quartz, but with the epithet "oriental" it means purple corundum and even purple spinel; at the same time, some jewelers use this name to denote the brilliant quartz from Siberia, characterized by alternating stripes of purple and white.
The name "diamond" is used to refer to a brilliant, extremely hard and, if cut correctly, brightly sparkling stone, which for all generations has been the most popular among gemstones. Unfortunately, this name was also given to shiny colorless stones of other species; Cornish diamond, Bristol diamond, and similar stones are rock crystal (colorless quartz), Mater diamond and Ceylon diamond — colorless zircon, and Saxon (or Siberian) diamond — colorless topaz.
Aquamarine is a beautiful bluish-green variety of beryl; Oriental aquamarine and Siamese aquamarine are greenish corundum and green spinel, respectively.