Please explain how shell dealers
Shell dealers and their shell-buying
customers worldwide use the HMS-ISGS Shell Grading Standards.
These standards, first published in the Hawaiian Shell News
in September 1977, are as follows:
A perfect specimen with
an unblemished spire, unbroken spines and lip without chips,
fully adult and normally colored -- a shell without a visible
flaw. Well cleaned inside and out, with original natural gloss
and color. Bivalves must have both valves, matched and unbroken.
An adult shell with only
minor flaws and with not more than one shallow growth mark.
Must have original color and gloss. A cone lip may have one
small chip, a murex two minor frond breaks. No repairs, such
as filed lips, mended knobs or filled worm holes.
A reasonably acceptable
shell with a few defects such as growth marks, broken spines,
worn spire or lip chips. Specimen may be subadult, but still
must faithfully display all the characteristics of the species.
May be obviously dead or
beach collected, with chipped lips, faded color, growth faults
or imperfect spires. Shells of Commercial grade are not acceptable
for mail order retailing and should not be offered as collectors'
Grades may be abbreviated as G, F, Gd. & C.
- W/O = with operculum.
- F/D = full data (area of
origin, habitat, date and original collector).
- B/D = basic data (less than
- + (plus) or - (minus) may
be used with quality label (i.e., G- or F+) in borderline
- JUV = juvenile, for Good
and Fine only, in lists, tags and letters.
These standards are constantly
being questioned and tested as users encounter new needs. For
instance, the scientific value of shells depends on the locality
data more than the condition of the specimen. Minor breaks and
flaws often allow one to infer something about the animal's
lifestyle and its predators. Many believe that the grading of
locality data (F/D, B/D) should now be divorced from the grading
of the quality of the specimen.