Gosh, Art.
 
Why is anything the way it is? Who says the deep water shells have
to be white? Why not gray, or black, considering all the muck down
there?
 
I suspect that, since the ocean doesn't have just calcium carbonate
in solution, other minerals and compounds get mixed in and, well,...
Color Happens!
 
Of course, none of that color is seen until you bring the shell
out of the abyss and into the light, or take a light into the abyss
(along with yourself to perceive the color).
 
And, to those we consider cursed with color-blindness, we are raving
loonies -- always bothered by this unseeable (to them) thing or that
unseeable thing.
 
I love to ask "Why?" and I have learned lots of things (but not nearly
enough). One of those things is the answer "Because." Some people
use it 'because' it's handy but sometimes it's used 'because' it's
the answer.
 
Why is an 'alimantary terminus' like SoDamn Insane allowed to
screw up so many peoples lives? I guess ".... Happens!"
 
Aloha,
 
makuabob (a.k.a. Bob Dayle)
 
 
 
MR ART WEIL wrote:
>
> Dear Paul;-
>     Your answer gets us right back to the beginning: which is: Why do
> mollusks living at depth have color at all? If color serves no
> function at depth, why are not all deep shells white?
>                 Art