According to the international gemstones classification, there are only 4 stones, that are classified as “precious stones,” and they are, namely: the Diamond, the Emerald, the Ruby and the Sapphire + the natural Pearls. All other stones are, actually semi-precious.
However, during the centuries, this list of precious stones has been changed for many times. It is obviously depended on the actual vogue in general, and on the stereotypes and customs, in particular.
Thus, at different times, the Opal has been presented on that list, but later, the vogue has changed and many negative peculiar features were attributed to this gem. Peridot, more accurately, chrysolite has been also in vogue, but later left the charts, due to the facts that, many chrysolite mines were detected. All the red stones were called the “Ruby” by our predecessors, until such time as modern scientists separated these gems. Topaz was also considered as “precious stone,” but many authors confusing in the opinion, whether it was definitely a true Topaz or not.
Hence, today we have an international standard, concerning these 4 gemstones, therefore we have to consider them as the true precious stones.
The List of Precious Stones of First Grade
Diamond is the most famous precious gemstone, possesses highest hardness and brilliancy, however, is not, actually, the most expensive, despite common opinion. Nonetheless, this gemstone has rich history and has encircled by the myths and legends. This gemstone has been chosen as a birthstone, appropriate for April. Read more about precious stone Diamond
Emerald is most expensive among all precious stones if contains no flaw. It was discovered in Peru by Spanish conquerors, however, it has been known to the Egyptians and even to prehistoric man, though it is worth noting, that our ancestors called all green stones “Emerald.” Emerald symbolizes the Birthstone for May. Read more about precious stone Emerald
Being a precious variety of Corundum, Ruby ranks almost equal place with Emerald in its value, though chemically it is almost the same precious stone, as Sapphire. Ruby of so-called “pigeon’s blood” color is quite rare and esteemed higher than a regular Diamond. Ruby considered as a precious stone appropriate for July. Read more about precious stone Ruby
Sapphire is actually deep-blue Ruby, while its color is the most valuable quality of this precious stone. Sapphire is next to the Diamond in hardness (9/10) and is equal to the Ruby in other qualities, except the color. It is the most magical and sacred stone of the ancients. Today this precious stone is associated with September Birthstone. Read more about precious stone Sapphire
Natural Pearls are also considered as precious stone, however, a Pearl, being a product of wildlife, is not a gemstone as such. Nonetheless the natural Pearls are precious, despite this fact, though it could be classified separately. Pearls possess a rich history on a level with the Diamond and other precious stones. A Pearl is the Birthstone for September, as well. Read more about natural Pearls
Rare Gemstones or Precious Stones of the Second Grade
There are some gemstones that are too rare, that are classified as precious stones, though they are not included into the official list of precious stones, however, they are still precious, therefore, I, with your permission, would classify them as the precious stones of the second grade.
Natural Alexandrite is a quite rare gem primarily of Russian origin. This gem owes its name to Russian Tsar Alexander II. It was discovered in Uralian emerald mines in 1883 by Finnish mineralogist. Its deposits are limited and actually exhausted, in regards to the Russian and Sri Lankan mines, however, there are some new mines in Brazil, South Africa and Madagascar, that probably could produce some pretty good specimens. Read more about Alexandrite
Tanzanite — extremely rare, unique gemstone, discovered in Tanzania by a young emigrant from Goa Manuel D’Souza in July 1967, whence its name, which subsequently has caused the so-called “Gems Rush” in the vicinity of Mount Kilimanjaro. This gemstone possessed a rich modern history, and, although, isn’t included in the list of the precious stones “de jury,” is considered as a precious stone “de-facto.” It is included in the modern Birthstone chart, as an alternative Birthstone, suitable for December. Learn more about the genuine Tanzanite