Here's a question/gray area:  would removing surface dull spots on shiny
shells be considered "Altering" the shell?  (i'm into cutting
stones/lapidary arts, I can completely remove surface dull spots (like
where a growth was attached), but i'm worried; i don't want to destroy
the value of the shell)

Ross Mayhew wrote:

> Jim Cordy brought up the topic of shell grading, so i just thought i'd
> review it again - what the heck??
>
> Below is the scale as it is usually applied.  That said, it is a very
> subjective activity:  some poeple like to call things "gem" that are not
> in fact perfect (i get a real chuckle when i look at a list and see 80%
> of the shells "gem"), and almost everyone tends to overgrade at one time
> or another - "caveat emptor": check everything yourself.   There was a
> movement a few years back to create a new category of "super gem", for a
> gem shell with its original operc, and some people think that the
> concept "gem for the species" is a valid one for species that almost
> never occur in a true gem state.  For me, F+ is a nice, collectable
> shell, but i am not a "gem maniac" :-=}.  Generarally if you want
> everything perfect you should have lots of loot or lots of time and patience.
>
> Gem:  completely perfect to the naked eye - no scars, pits, dull places
> on shiny shells, etc.  There is a bit of leeway on growth lines (places
> where the growth of the shell has stopped for a while then resumed, for
> reasons of disease, lack of food, temperature extremes, etc.): most
> people would agree that one or two very  thin growth lines do not change
> the grade of shells like cones or volutes.
>
> Gem-/F+++:  These grades are exchangeable.  I prefer Gem- myself, but
> you can't fault someone for using F+++.  This is a shell so close to
> perfect that you really have to look CLOSELY in order to see the imperfection.
>
> F++: VERY high quality: extremely tiny flaw(s): This is a primo shell!!!
>
> F+ high or F+/F++:  better than F+ but not quite up to F++ standards.
>
> F+:  This is the true grade (in my opinion) of most shells sold or
> collected: it is a good quality shell with a couple of small
> imperfections that do not really detract from the attactiveness of the
> specimen - say a small chip or two from the lip, a couple of moderate or
> several smaller growth lines, a natural repair mark or two that doen't
> mar the shell for most folk's appreciation, etc.
>
> F/F+:  Almost F+, but getting a bit dicy:  ok for rare species or forms
> or very interesting shells that one might not get another chance to get
> soon, or perhaps just not at the price or trade value offered.
>
> F: A shell that has a number of minor to moderate problems, or one big
> one (such as a nasty scar or a broken lip or a number of heavy growth
> scars:  for F shells the attractiveness is affected. Good for scientific
> purposes, however, or for "place holders" of a species or form, or for a
> really unusual shell.
>
> Good: Not good.   Nasty stuff happening.
>
> Fair: Not fair at all!!!  Recognizeable as the species or form but
> beyond that.....
>
> Poor: Recognizeable as a shell.
>
> A dead-collected shell can be any grade at all - even Gem if the animal
> died or was murdered minutes before the shell was nabbed!!  I think
> there is a bit of discrimination going on regarding very high-end dead
> collected shells: you have to price them quite low before they sell at all.
>
> Protoconchs are important: it is questionable to call a specimen without
> one F++, although if only the terminal whorl or so is gone and the rest
> of the shell is in fact perfect, it's not so much of a crime.
>
> The prescence of periostracum or an operculum is noteable - of course in
> many species if the perio is still clothing the specimen, the true grade
> is impossible to determine since the surface of the shell is obscured.
> On the other hand, a land snail without perio is nearly useless, since
> this is where much of the patterning and pigmentation is present for
> these guys.
>
> A shell that has been altered (lip filing is the most common form of
> "alteration") in any way, or repaired, cannot really be graded since it
> is not in its natural state.   Despite the fact that 99% of
> conchologists have nothing to do with altered shells, the practice is
> becoming more common than ever, and in the case of some of the new
> coatings can be VERY sophisticated.  That's a topic for another time -
> it would be a GREAT idea if someone would write a "definitive" little
> pamphlet about the myriad ways shells can be "artificially aesthetically
> enhanced" - and how to spot them without using rocket science!!
>
> That's my 2 cent's worth on grading: hope it's of some value to someone!
>
>>From the middle of nowhere (but what's wrong with that??),
> Ross.
>
>


--
Steve                      _
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"I have opinions of my own -- strong opinions -- but I don't always
agree with them."
        - George Bush, former U.S. President