In a message dated 8/17/1999 7:22:41 AM US Mountain Standard Time,
[log in to unmask] writes:

<<  Over time some
 >glass tubes can chemically attack shells stored within. It depends of the
 >additives in the glass. I got 24 000 50x6mm testtubes at a technician's
 >sale. These are great for micros, except...after several years I have found
 >some specimens growing crystals. These are of two types; fine white hairs
 >which can completely hide the shell, and small white cubes. I don't know
 >what their compositions are or how to counter the problem,  >

John Wolff
Maybe the glass tubes had a remaining residue left from what the tubes
originally held.  And if it was chemicals, who knows how it reacts with the
shell compounds and (if Marine) salts.
April