Klarinet Archive - Posting 000866.txt from 1997/02

From: Oliver Seely <oliver@-----.EDU>
Subj: Re: glass/crystal
Date: Tue, 25 Feb 1997 14:13:44 -0500

The use of the two terms for me as a chemist is both problematic
and irritating. Problematic because a crystal is a body formed by
an element or compound solidifying so that it is bounded by plane surfaces
symmetrically arranged which reflect a definite internal structure. A
glass is a material not yet in a crystalline state but whose amorphous
structure has been frozen in place by cooling below its softening point.
The use of the word crystal is also irritating to me because it is a bit
of a con. The fourth definition of "crystal" in my old collegiate dictionary
is "glass of superior brilliancy, made into articles for the table, etc."

So unless your mouthpiece was made by chipping away at a piece
of quartz crystal and carved and ground meticulously with carbide and
diamond grinding tools or cast in a mold at its melting point of 1610 deg. C.
it probably isn't crystal, but some form of glass (of superior brilliancy,
OF COURSE, so that the manufacturer can justify charging more for it).
In any case I'd be interested to read the posting of an authority on the
subject
who could tell us what the average melting point is of these various hard and
transparent mouthpieces for which the word "crystal" is bandied about so
casually.

Oliver