Re: Yes, there is a Mineral Definition

I am delighted by the discussion, and should spoil my point if adding 
anything. But I can't help imitating that old tune ("Yes, we have no 
bananas!") by saying:"Yes, there is no TRUE definition of a mineral". 

Like any attempt to find an indisputable, rigorous and self-contained 
foundation for a basic concept, it is futile (cf. Goedel's theorem.)

If I am allowed to add some more topical flavour to the discussion and 
to my argument: 

I contend that the use of a rigorous definition is now a hindrance 
for progress in mineralogical research. The universal stance of 
founding any research on thermodynamical calculations based on defined 
compounds tends to skip legitimate observations of ill-defined ones 
(frequently observed by means of the SEM/EMP).

There is plenty of "mineraloids" at the "bottom" (i.e. at the nanometric
scale, cf. Feynman), whereas they are still too often pushed towards the
foonotes in handbooks. Most of mineralogical and crystallographical
research
we are speaking about here was done with minerals measurable at the 
millimetric to micrometric scales. (I don't of course despise works made
with TEM=transmission electron microscopy). But does a "mineralogical
species" which is only observable and definable by TEM already accepted
without recrimination?

Mineraloids are especially important for stepwise and continous
geochemical alteration and transfer phenomena in the making. "Fully"
definable minerals can be considered mostly as end points or relatively
stable stages. But they help of course, and should be thoroughly known and
tought.(Cheers to Bob!)

Those interested in an illustration of my point via my pet subject
(Unconventional Platinum Group Minerals and Mineraloids=UPGMM) will find 
materials at the following websites:

http://www.ulb.ac.be/sciences/upgm
"  "  "  "  "  "  "  "  "  " /katangapgm
"  "  "  "  "  "  "  "  "  " /uralirite/uralirite.pdf
 
J.J.