Gem — Perfect quality specimen that’s in the naked eye only.

F+++/Gem — Minimal imperfection sometimes unnoticeable mark and can be gem to mostly.

F++/F+++ — Has blemish, but doesn’t detract the beauty of the shell.

F+/F++ — Has obvious flaw, but still very collectable.

Fine — Less likely to be offered unless for a very special reason.

Dead – Dead or fresh dead collected.

N/R – Niger or Rostrated or both.