It is true that high magnification will often reveal minute flaws which
cannot be seen with the unaided eye.  However, I believe it is a given that
any grading system is based upon the appearance of the specimen to the
unaided eye. We often say that "gem" means a "perfect" or "flawless"
specimen. But actually, a more accurate description of "gem" is "no flaws
detectable with the unaided eye, even on close inspection".  A shell which
meets that standard is "gem", even though a fine scratch might be seen at
20x magnification.

----------------------------------------------------------------------
[log in to unmask] - a forum for informal discussions on molluscs
To leave this list, click on the following web link:
http://listserv.uga.edu/cgi-bin/wa?SUBED1=conch-l&A=1
Type your email address and name in the appropriate box and
click leave the list.
----------------------------------------------------------------------