The term "precious" is defined by the dictionary as "having great value"; "semiprecious" refers to something of "lesser" value. The dramatic rise in the prices of all gemstones during the 1970's has made these terms completely obsolete. However, they remain familiar to many jewelry buyers around the world, and therefore retain colloquial use. The term "precious," as applied to gemstones, has (for centuries) traditionally referred to four stones: diamond, emerald, ruby and sapphire. These "precious" gems when found in their respective top qualities, can be considered like "blue-chip" stocks and form a basis of most fine gemstone collections and portfolios.