Scott,
 
An entire book could undoubtedly be written about fakes.  Most that I have seen
were inexpensive shells doctored to look like expensive shells.  For instance, a
Cypraea tigris painted to look like a Cypraea aurantium or even a Cypraea
aurantium painted white to sell as an albino.  Other processes I have read about
include heating a shell such as Conus marmoreus to turn it orange colored or all
of the filing, sharpening, etc. just described on the list.  I did have a nice
fake Conus hirasei that I assumed was a painted shell of a more common species but
Mark Bethke (who knows much more about cones than I do), after he got it in a
trade with me pronounced that he thought it was a constructed shell!  So there you
go.  How it was done is a complete mystery to me.  Our best defense against all of
this has been the honesty and experience of dealers who could spot a paint job
that lacked the depth and luster of a real shell or took the trouble to check for
filling, repairs, and touchups.  With the fakery becoming more sophisticated, this
line of defense is certainly weakened.  But it sure keeps it interesting -- what a
great hobby!
 
Oh, when Art mentioned coin collecting and filing the slot with a less than
perfect coin, he neglected to say that the coin world also has its fakes.  My
Grandfather collected coins for years and kept one in a safety deposit box.  This
was one of three of these coins known to exist.  When he finally decided to sell
it, he had it checked to verify its authenticity.  As most of you have guessed, it
was a fake.  Someone had pressure molded an old Roman coin into the image of this
rare coin.  If money is involved....
 
But now I have to go check out a couple of shell lists and see what they have that
I can not live without.  As I won't be looking for any Cypraea leucodons, I will
not worry over much about fakes.
 
Tom Eichhorst in New Mexico, USA