[meteorite-list] Term Main Mass +add

[Eduardo.]

I made some internet search and found the following "definition" of main 
mass at http://www.meteoritekit.com/glossary/

Main Mass
The Main Mass refers to the total pre-atmospheric mass of a meteoroid or 
the largest known fragment of a meteorite. 

thats the strangest definiton of main mass I ever read!


In my opinion, the main mass is the largest fragment or piece collected 
after a fall/found of a specific meteorite fall. If you cut it, each of 
the fragments came from the main mass, and the largest of them is now the 
main mass... unless a the 2nd larger specimen of that fall/find is larger 
than all of the fragments, then the main mass is gone forever. So the 
main mass is the largest fragment of the largest specimen collected if 
it's still the largest known piece of that fall/find.

Going now to desert meteorites, if you are 100% sure that two specimens 
came from the same strewnfield, and they are paired, then only one of 
them should have a main mass. In paired DAG's, for example, where you 
know where they were collected, only one of the pieces should be the main 
mass (so, several DAG numbers, one main mass). In most of the NWA, as 
they are bought from nomades this is almost impossible to be told, so 
each NWA number have it's own main mass. Of course the meaning for a 
collector of having a main mass from a NWA and one from other locality is 
not the same.

This year I was able to obtain the first main mass from a Fall in my 
collection (according to my definition). It was a 1.4kg specimen of Arbol 
Solo, fall on 1954, Sept 11. The TKW until last year was 899g. Now it 
went to 2.3kg. 
Now the add, I will have a few specimens taken from the main mass at 
Tucson. Less than 150g was cut and no more will be cut from it 
(preserving the main mass in my collection). Most of the rest of this 
meteorite is locked or lost. If you want to see them just stop at my room.

Eduardo


-----Original Message-----
From: star-bits at comcast.net
To: meteorite-list at meteoritecentral.com
Date: Fri, 20 Jan 2006 07:13:13 +0000
Subject: Re: [meteorite-list] Term Main Mass

> 
> Since you are collecting opinions I'll give you 2 of them, my 2 cents
> worth so a penny each.
> 
> First the cynical one - Buyers like to own main masses, sellers like to
> sell things.  The looser the defination of main mass the more there are
> to sell.  Buyers are happy, sellers are happy.
> 
> Second my personal defination.  If a stone isn't at least 1/2 the total
> mass recovered from the fall it isn't a main mass.  Since the total
> mass recovered from the fall is unknown for NWA meteorites none of them
> qualify.   That defination eliminates 98% of the so called main masses,
> Norton County being one of the few qualifiers.   Buyers won't like that
> defination because it makes main masses virtually impossible to own. 
> Sellers won't like it because it removes a sexy selling label.   But it
> makes it easy for me to put together sales pages.   I have never owned
> a main mass by my defination and have therefore never listed a
> meteorite as a "main mass" at my web site.  It is my personal
> defination which I don't expect to see adopted in the meteorite
> community, but it suffices for me.
> 
> --
> Eric Olson
> ELKK Meteorites
> http://www.star-bits.com
> 
>  
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