[meteorite-list] MOLDAVITE COLORS

[Sterling K. Webb]

Hi, List, and Mike Gilmer who asked originally,

Yes, Mike, it is the iron.

Moldavites are high in Si02, usually close to
80%. that is, they have a higher "glass" content
and fewer "minerals." The most common other
ingredient is Al203, from 8% to 10%. Fe0 makes
up only 1% to 2%, and it is this iron-poor recipe
that makes them green and gem-like.

Moldavites range in color from a very pale green
to a brown that can be as dark as a light Indochinite.
The color is determined by an increase in the ratio
of trivalent iron over bivalent iron over the range of the
green-to-brown spectrum. The index of refraction and
the density increases in the same way.

Almost every type of splash-form known from the
Australo-Asian strewnfield are found in moldavites
as well, but "drops" and "dumbbells" are rare. There
are Muong-Nong moldavites found in the Budejovice
region, but no aerodynamic buttons have ever been
found.

Moldavites have many forms unique to them, like the
"leaf" type. Moldavites frequently contain trains of
gas bubbles, Occasionally, a two-colored moldavite
is found, formed when two plastic moldavites collided
in flight and stuck together. And Bog Haag has the
one and only known YELLOW one.

And while I typed this and checked the figures, the
question was answered already...


Sterling K. Webb
--------------------------------------------------------------------
----- Original Message ----- 
From: "Chris Spratt" <cspratt at islandnet.com>
To: <meteorite-list at meteoritecentral.com>
Sent: Friday, December 10, 2010 12:15 PM
Subject: Re: [meteorite-list] Mineral responsible for green color 
inMoldavite?


>I think it may be a form of Beryilium or Beryl.
>
> Chris. Spratt
> Victoria, BC
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