Grade Definitions

Presentation Grade is the highest grade of Mother of Pearl obtainable. This grade of pearl has no fractures, defects, discoloration, holes or unfavorable markings.

"A+" Grade is very similar to Presentation grade. Usually, this grade will have one very minor flaw at one end of the scale. This flaw will usually include yellow coloration, and/or a slight fracture. Usually, this flaw can be cut around or trimmed away.
"A" Grade is also a very high grade of pearl. Pieces will have a flawless front side. The reverse side will generally have minor shallow fractures, some yellow coloration, and/or a slight worm hole that can be avoided.
"B" Grade is still a workable grade of Mother of Pearl and is commonly used by beginning knife makers or knife makers that make relatively inexpensive knives. "B" grade Mother of Pearl will still have a flawless front side. The reverse side will have some deeper fractures, more discoloration, a larger worm hole that has been filled, and/or some exterior bark.

Mother of pearl is the common name for iridescent nacre, a blend of minerals that are secreted by oysters and other mollusks and deposited inside their shells, coating and protecting their bodies from parasites and foreign objects.

Nacre is the same substance that is deposited around an object that becomes lodged in the mollusk--either naturally or inserted by humans--to become a pearl.