Fluorescence and Mineral Identification {was: Re: [Rockhounds] fossils}

[Earl R. Verbeek]

Kreigh wrote:

> But there are very few minerals that can be reliably identified from a
> variety of localities based on fluorescence. 

I agree; this is simple observational fact.  However, in place of the word
"fluorescence" above, you could insert almost any other property of minerals
(color, hardness, luster, cleavage, radioactivity......) and the statement
still is true.

Nate had it exactly right in his last post, that a variety of attributes
used in combination is how we identify minerals, and fluorescence is one of
those attributes that some of us use habitually.  Kreigh is right, however,
that a good working knowledge of how minerals fluoresce is not as easily
obtained from the standard hobbyist (or even professional) texts as
information on other mineral properties, and Don Halterman provided a good
explanation for why that is.  As an identifying attribute, fluorescence is
much more valued in gemology than mineralogy, in part because people
generally take a dim view of scratching a cut gem or breaking it to observe
cleavage or fracture to identify it.  Fluorescence has the advantage of
being a nondestructive test, and in most of the standard gemology texts
you'll find it discussed and tabulated for each gem species.  That doesn't
solve the problem for much of the mineral kingdom, though.

           Cheers-   Earl