We can perform qualitative chemical analysis
($30 per sample), X-ray powder diffraction, and Raman spectroscopy
($40 per sample).
We offer a new, relatively inexpensive, element-ID service for minerals
that we have found from personal experience to be just what is needed
to settle many mineralogical questions.
Using Emission Spectroscopy to examine chemical element spectra generated
in an electric arc one can identify (or rule out) key elements in minerals.
Actual examples have been to distinguish with certainty between Australian
Wulfenite and Stolzite by identifying the molybdenum or tungsten spectral
lines. Other examples: pink Chinese morganite or apatite? in this case
the chemical phosphate test gave an unequivocal answer. Banded white
smithsonite or something looking like it? (Result: strong response to
zinc and carbonate). We use a combination of methods becouse no method
is complete.
When you can define your ID problem in terms of the presence or absence
of a key element or chemical moeity we can probably help. If so we will
ask you to send us a representative fragment (from a portion of the piece
that does not hurt your specimen) . A small plastic bag in a regular
envelope will probably suffice for analysis. Cost is $30.
X-ray powder can identify on the order of 95% of all minerals. Minerals
which cannot be distinguished are species with identical structures and
similar sized ions. For example, siegenite and violarite have nearly
exactly the same cell parameter (+/- 0.01 A) and thus cannot be distinguished
by X-ray.
Powder work requires approximately a 2 mm cube of material.
I would prefer that you send a chip of the mineral, in a plastic bag,
box or gelatin capsule, which I can powder for X-ray work. Some fibrous
minerals (such as zeolites) require more material (as is also the case
of a mineral like oyelite). I believe that you could simply mail most
such samples in a standard envelope, which is much cheaper than actually
packaging the stuff.
RAMAN spectroscopy has the advantage of being completely nondestructive,
but only a few hundred minerals have published patterns. For example,
this is useful for identifying a perfect gem crystal since you will not
damage the crystal at all in the sampling. IN this case, the entire specimen
should be mailed via insured shipping, and will be returned after testing
(you must pay return shipping costs).
I recommend consulting via email before sending over samples.
I could determine if X-ray will identify your sample, or possibly if
RAMAN would suffice.
-Rob Lavinsky
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