[Rockhounds] Re: Organic/Inorganic: What Is A Mineral? + Mars minerals

[DonH]

pmodreski at aol.com wrote:

> Of course, Don.
> 
> But if we "officially" amended the definition of a mineral to simply be "any naturally occuring crystalline compound or element" which is what some would advocate,?then where/how do we stick in the caveat that we still want to exclude any crystalline forms of sugar, starch, cellulose, DNA, amino acids, proteins, or whatever else is strictly completely 100% biological?


Well, we can draw a fuzzy but thick line at the border of non-solid, 
short-range-ordered substances.  There are people who already specialize 
in those materials.

I think you are making a straw-man argument.  Mineralogists specialize 
in materials that are *usually* inorganic but may have organic 
analogues.  It seems to be a matter of making the borderline a little 
more permeable, rather than trying to make inorganic and organic 
chemistry one big happy family.

For example, someone from another department wanted help determining 
what was precipitating out of their foul solution (which contained urea 
and smelled like an outhouse).  By using the polarizing light microscope 
  and the x-ray diffractometer, we determined there was calcite as well 
as some some sort of ammonium salt.  After that, we advised them to take 
it to the chemistry dept.  Now, we didn't originally say "no we won't 
help you, that's biogenic," but after we had done what we could in the 
mineral realm, we referred the issue elsewhere.

And while I'm on the subject, we occasionally look at a materials 
science problem.  That's a trend, and in fact I've taken to calling 
"American Mineralogist" as "American Materials Scientist."

Well I hope that makes some sense, but I must move on and work on some 
other things now.

best,
Don