A gemstone is the naturally occurring crystalline form of a mineral, which is desirable for its beauty, valuable in its rarity and durable enough to be enjoyed for generations.
 
Traditionally, gems classified as precious were those that were both rare and revered. While market availability, or lack thereof, was one characteristic of a precious stone, the more important factor was how that stone was used. Gems that held ceremonial or ecclesiastical value for royal or religious figures were substantially more valuable.

These “cardinal” gems included diamonds, sapphires, rubies, and emeralds. Originally, amethysts were also considered precious, but generous deposits of the purple gem found in Brazil made it available and affordable for the public, and it was no longer labeled a precious stone. Only these five types of gems were ever considered precious, and today, there are more than 130 types of stones that may be considered semi precious gemstones.

In reality, there are no true differences between precious and semi precious classifications. A low quality diamond, for example, may be far less valuable than a high quality aquamarine, and their respective prices will not match up to arbitrary classifications. Whether or not a stone is precious to a specific individual should depend more on preferences, budget, and personal symbolism than on outdated and irrelevant classifications.

In order to assuage consumer confusion, the Federal Trade Commission periodically considers banning the use of the terms precious and semi precious entirely. With many high quality synthetic and treated gems available in the marketplace, other classifications are relatively meaningless and a stone’s certificate should outline all the necessary information to determine how precious it truly is.