A rectangular or square-shaped cut-cornered diamond.
The characteristic of a polished diamond that accounts for the risk of damage inherent in its proportions (i.e., the risk of chipping in diamonds with extremely thin girdles).
When light enters a diamond it reflects off the facets and the angles cut into the stone. This distribution of light is known as dispersion, or the display of the spectral colors.
Abbreviation for pennyweight
There are many recognized gemological laboratories that can grade your diamond for a fee. The most well known is the GIA, Gemological Institute of America.