Important Terms Relating to Diamond Buying
The following are some terms that relate to diamonds and other gemstones.
AGS: The AGS, or American Gem Society, is an educational institute that focuses on gemological studies. The AGS developed the standards that are used today when grading a diamond. Color, cut, and clarity are major factors that affect the value of a diamond.
Blemish: A blemish is an imperfection on a diamond’s surface. Some blemishes do occur naturally, but most blemishes occur after a diamond has been removed from the earth.
Crown: The crown is the upper part of a gemstone that has been cut. This portion of a diamond or other gemstone lies above the stone’s girdle. In an engagement ring, wedding ring, and other jewelry, the crown is what typically sits up above the setting.
Eye-clean: An eye-clean gem is one that has no imperfections that are visible with the naked eye. An eye-clean diamond or other gemstone may have imperfections that are visible with a microscope or other equipment, though.
Feathers: Feathers are tiny cracks in a diamond, which often appear feathery when viewed under a microscope. Feathers may be entirely within a diamond, or they may extend to the surface of the gemstone. A diamond with feathers is not necessary excluded from use in earrings, pendants, or other jewelry, but care must be taken with the gem to avoid increasing the damage. Feathers are typically naturally occurring. They often form when the diamond experiences pressure underground while it is forming.
Girdle: The girdle is the band around a cut gemstone. It sits at the base of the crown. Girdles can be unpolished, polished, and even faceted. Depending on the particular gemstone cut, a girdle’s thickness will vary.
Inclusion: Inclusions are imperfections that are found on or within a diamond. Inclusions only refer to imperfections that occur naturally on or in a gem, like feathers.
Pavilion: The pavilion of a diamond or other cut gemstone is the bottom portion of the stone. The pavilion sits below the girdle, and it is often covered by a jewelry setting. Like the rest of the diamond, the pavilion contains many facets.