Hello Halim,
Yes, there are occasional albinistic specimens of Nautilus pompilius. They
are extremely rare. I believe such a specimen was offered at the
Conchologists of American convention a couple of years ago, either as a
raffle prize or an auction item???
Here is my take on the shell grading system. These descriptions are not
"official", but they work for me, and I feel that they accurately reflect
the intended purpose of the system. I am open to other opinions:
"gem" - a specimen with no flaws detectable by the unaided eye
"fine plus plus" (f++) - a minute flaw, difficult to detect, even on close
inspection
"fine plus" (f+) - one or two small flaws, not readily noticeable except on
close inspection
"fine" (f) - one or two significant flaws, noticeable on casual inspection,
which do not greatly compromise the scientific or aesthetic value of the
specimen
"good" - major flaws, but still showing the principle identifying
characteristics of the species
"Gem" is usually described simply as "flawless", but I prefer to describe it
as above (pardon my compulsion for accuracy - I'm a scientist). In my
humble opinion, an absolutely perfect shell is an extreme rarity. Give me
your best "gem" cowrie and a good 50-power microscope, and I'll find a few
flaws for you. But such microscopic imperfections do not require that a
shell be downgraded from "gem".
Some dealers list shells as "fine+++" or "fine++++" or "fine
++++++++++++++++", to indicate a specimen that is virtually - but not QUITE
- gem. I suppose this is warranted in some cases, though generally
speaking, I think the use of extra "+" signs just confuses the issue.
Others use "gem-" (gem minus) for the same purpose, or simply describe the
specimen as "near gem". To my way of thinking, "fine++" is supposed to mean
"near gem", so I usually just stick to the basic categories listed above.
I base grading on both the severity and the number of visible flaws. A
shell with one minute flaw would be fine++. A shell with a more significant
flaw would be downgraded to fine+. But a shell with several minute flaws,
as severe as the flaw on the fine++ specimen, would also be downgraded to
fine+.
Paul M.
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