Examples of quality marks on jewelry include Kt., Ct., K and C. However, quality marks differ depending on the material of the jewelry. Examples of jewelry terms include "adularescence," "adamantine" and "alloy."
The markings Kt., Ct., K and C stand for karat and carat, which are units of measurement that pertain to gold and gemstones. The purity of gold is measured in karats, with 24 karats being the highest quality possible which is pure gold. If a gold piece is marked as being 10 karats, that means 10 of the 24 karats are actually gold. The weight of a gemstone is measured in carats. One carat is equivalent to 1/5 gram.
Examples of silver quality marks include 925, 9.25 and .925. These marks are used on pieces of jewelry that contain a minimum of 92.5 percent of pure silver.
"Adularescence" is a term that describes an optical occurrence in which a soft, shimmering light moves within a gemstone when the stone is rolled back and forth. This phenomenon is commonly associated with moonstones. "Adamantine" is a term used to describe any stone that features a diamond-like shine. Examples of rare stones that exhibit this luster include cerrusite, sphalerite and demantoid.