sea shell parameter ???

[paul monfils]

First I should say that grading of shells is always a somewhat subjective process, and even among experienced and knowledgeable collectors and dealers there is bound to be some variation.  One person's fine+ will be another person's fine++. Still, there are some general guidelines, and they usually read something like this:

gem = a flawless specimen, no defect of any kind that can be seen with the unaided eye, even upon close inspection.

fine++ = a minute flaw, unnoticeable upon casual inspection, but which can be discovered upon close inspection; "nearly gem".

fine+ = a small to moderate flaw, noticeable upon casual inspection, but which does not seriously compromise the scientific or aesthetic value of the specimen.

fine = an obvious flaw which significantly detracts from the aesthetic value of the specimen, though not necessarily from its scientific value.

good = a specimen with major damage, which can still be accurately identified, and may have some scientific value. Such specimens are usually not offered by dealers or sought by collectors, but a museum might welcome such a specimen of an extremely rare species which is never available in better condition.

Note that this grading system is based upon viewing the specimen by the unaided eye (other than by normal corrective lenses). A Cypraea might have a miniscule mark that can be seen with a good quality 20X microscope, but if it cannot be seen by the unaided eye the shell can still be graded "gem". Some dealers like to use additional + signs (fine++++), but in my opinion this is essentially meaningless. Fine++ means "virtually gem", and additional + signs really don't add anything but confusion.