What is considered a precious gem?
According to Wikipedia “A gemstone (also called a gem, fine gem, jewel, precious stone, or semi-precious stone) is a piece of mineral crystal which, in cut and polished form, is used to make jewellery or other adornments. However, certain rocks (such as lapis lazuli and opal) and occasionally organic materials that are not minerals (such as amber, jet, and pearl) are also used for jewellery and are therefore often considered to be gemstones as well. Most gemstones are hard, but some soft minerals are used in jewellery because of their lustre or other physical properties that have aesthetic value. Rarity is another characteristic that lends value to a gemstone.”
The concept that some gemstones are “precious” and others are merely “semi-precious” is familiar to every buyer of coloured stones.
The term “precious gem” is usually used to describe the scarcity or monetary value of a gem. However what is considered a “precious” gem differs depending on the part of the world in which you are and also the cultural associations.
As Wikipedia continues “The traditional classification in the West, which goes back to the ancient Greeks, begins with a distinction between precious and semi-precious; similar distinctions are made in other cultures. In modern use the precious stones are diamond, ruby, sapphire and emerald, with all other gemstones being semi-precious. This distinction reflects the rarity of the respective stones in ancient times, as well as their quality: all are translucent with fine colour in their purest forms, except for the colourless diamond, and very hard, with harnesses of 8 to 10 on the Mohs scale. Other stones are classified by their colour, translucency and hardness.”
Precious stones are typically identified as diamond, ruby, sapphire and emerald – they have historically commanded the highest prices due to their extraordinary colour or brilliance and their extreme rarity.
While the precious stones are deservedly famous, the conventional distinction between precious and semi-precious gems is laden with misconceptions. The distinction between precious and semi-precious gemstones is a recent innovation, dating to the nineteenth century. “Semi-precious” was used to denote “of less commercial value than a precious stone”.