The problem is that most of these mineral databases such as Mindat, RRUFF, Mineralienatlas and Webmineral now use ideal endmember formulae for amphiboles, and many other complex minerals groups as recommended by the IMA, . So there is now no such species as hornblende, and a search on Ca, Mg, Al, Si will result in numerous amphiboles, including magnesio-ferri-fluor-hornblende etc but not hornblende in the general sense. But that's usually good enough to give you some likely contenders or a mineral group, as long as you only enter the major elements determined. It would probably be useful to add formulae and more data for some of these old names deemed obsolete by the crystals chemists but still widely used by petrologists and geologists.
regards
Ralph Bottrill
Senior Geologist, Mineralogist and Petrologist
Metallic Minerals & Geochemistry
Mineral Resources Tasmania
PO Box 56, Rosny Park TAS 7018
Phone: 61 3 6165 4715 (NOTE: new!), m: 0429 173 055; Fax: 61 3 6233 8338
Email: [log in to unmask] or: [log in to unmask]
________________________________________
From: Metamorphic Studies Group [[log in to unmask]] on behalf of Pavel Pitra [[log in to unmask]]
Sent: Friday, 15 January 2016 10:47 PM
To: [log in to unmask]
Subject: Re: [geo-metamorphism] About EPMA data
Hi Xi and all,
this is a relatively frequent request from
students and would merit a good answer.
My understanding is that you have a chemical
(e.g. microprobe) analysis of a mineral a would
like to know the name. You don't have the formula
(since for this you first need to know what
mineral it is). The best I found for this purpose
is http://webmineral.com/chemical.shtml
It allows you to enter element names and weight
proportions (with some uncertainty) and proposes
you then a list of possible candidates. It's not
perfect, but works rather well.
I didn't know the sites proposed by Julien and
Francois, tried them now and didn't find them
really suitable for what I believe is your
problem - but if it's OK for you, then it's
perfect.
For example entering "Ca,Mg,Fe,Al,Si" in the
rruff database does not return hornblende or any
other "common" calcic amphibole.
In the Athena database, you need to know the
formula, and exactly in the form the database
likes it - e.g. entering "K Al3 Si3" (looking for
muscovite) only proposes WILLHENDERSONITE (that I
never heard about). In order to find muscovite,
you'd have to enter "K Al2 Si3" since the formula
is written as "KAl2[]AlSi3O10(OH)2". Not very
practical, I find...
I'm looking forward to seeing if others have some better approaches.
Cheers,
Pavel
---
>I wonder if any software that i just type in the
>chemical composition that I can quickly get the
>mineral name of it?
--
Pavel PITRA
Géosciences Rennes email: [log in to unmask]
Université Rennes 1 tel: (++33) 2.23.23.65.06
Campus de Beaulieu - Bat. 15 fax: (++33) 2.23.23.60.77
F - 35 042 RENNES CEDEX
FRANCE http://www.geosciences.univ-rennes1.fr/
http://www.geosciences.univ-rennes1.fr/spip.php?article67
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