Hello Dennis,

Welcome to Conch-L!

I took a look at your pictures.  On the first page, 6 of the first 7
pictures are of a pearled Turbo argyrostomus (silver-mouthed turban
shell).  "Pearled" means that the outer layer of shell has been removed,
to exposed the underlying pearly layer.  The second picture is also of a
Turbo (turban shell), but I can't tell the species with certainty, from
the rather limites portion of the shell that is shown.  It may be a
small Turbo marmoratus (green turban), or it may be another Turbo
argyrostomus.  This one is natural, not pearled.
Pictures 8 and 9 on that page are of a bisected Nautilus pompilius
(chambered Nautilus).  This is not a snail, but a cephalopod (a relative
of octopus and squid).
Pictures 10 and 11 appear to be of a pearled Turbo sarmaticus (South
African Turban).

On the second page, the top picture and the 2 bottom pictures are again
T. sarmaticus.
There is one more picture of Nautilus pompilius.
The rest of them appear to show the inner surface of a large abalone
shell (Haliotis).  Some of these show the natural pink/green
iridescence, and were presumably photographed with white light.  Other
views look like they may have been photographed while illuminated with
colored light.  Is that correct?

Regards,
Paul Monfils