[Rockhounds] REE -

Tue Jul 8 03:19:00 PDT 2008

Yes but Terlingua is no longer an active locality, I was told.
There are however many localities that produce calcite with a similar
fluorescence... The "so-called" Terlingua-Type calcites? ;-)))
We even find spots of REE-activated calcite in quarries in Belgian karst
areas. 
If I remember correctly it 's cerium(/lead?) + manganese/lead that cause the
pink fluorescence in long wave UV and cerium =>europium that are responsible
for the blue phosphorescence in short wave.

Cheers
Axel 

> -----Oorspronkelijk bericht-----
> Van: rockhounds-bounces at lists.drizzle.com 
> [mailto:rockhounds-bounces at lists.drizzle.com] Namens Glenn Wimpee
> Verzonden: dinsdag 8 juli 2008 5:25
> Aan: Rockhounds at drizzle.com: A mailing list for rock and gem 
> collectors
> Onderwerp: RE: [Rockhounds] REE -
> 
> Why "so-called"? Isn't Terlingua a real locality?
> Glenn 
> 
> 
> 
>  EMAILING FOR THE GREATER GOODJoin me
> 
> > From: axel.emmermann at pandora.be> To: rockhounds at lists.drizzle.com> 
> > Subject: RE: [Rockhounds] REE - > Date: Mon, 7 Jul 2008 21:51:51 
> > +0200> > Indeed my friend!> Cerium is also a good 
> replacement for Mn2+ 
> > in fluorescent calcite... The> so-called Terlingua Type Calcite.> 
> > Beautiful pink fluorescence under LW-UV.> > Greetzzzz > Axel> > > 
> > -----Oorspronkelijk bericht-----> > Van: 
> > rockhounds-bounces at lists.drizzle.com > > 
> > [mailto:rockhounds-bounces at lists.drizzle.com] Namens Rik Dillen> > 
> > Verzonden: maandag 7 juli 2008 19:35> > Aan: 
> 'Rockhounds at drizzle.com: 
> > A mailing list for rock and gem > > collectors'> > Onderwerp: RE: 
> > [Rockhounds] REE - > > > > REE are even used in some very special 
> > steel qualities nowadays.> > One of the purposes is to use it as a 
> > scavenger for sulfur. > > Manganese is used for that traditionally, 
> > but MnS has in some > > steel grades the tendency to form 
> large flaky 
> > pancake-like > > structures underneath the steel skin, which, in 
> > certain > > cases/circumstances might give rise to flake 
> formation. > 
> > > Cerium sulfide on the contrary forms very small, hard > > 
> spherical 
> > precipitates instead, which improves steel quality. > > The big 
> > drawback is the price, of course (in the steel > > industry 
> they don't 
> > need grams, but many tons).> > > > Grts,> > > > Rik DILLEN> > 
> > Doornstraat 15,  B-9170 Sint-Gillis-Waas Belgium E-mail > > 
> > rik.dillen at skynet.be Homepage : 
> http://users.skynet.be/rik.dillen > > 
> > > > > > -----Original Message-----> > From: 
> > rockhounds-bounces at lists.drizzle.com > > 
> > [mailto:rockhounds-bounces at lists.drizzle.com] On Behalf Of 
> > > Ronald 
> > Werner> > Sent: Sunday, July 06, 2008 11:36 PM> > To: 
> > rockhounds at lists.drizzle.com> > Subject: [Rockhounds] REE - > > > > 
> > Sorry Kreigh, but some correction is needed here!> > > > 
> REE are to my 
> > best knowledge NOT used for doping > > semiconductors. That's the 
> > privilige of the group III and V elements.> > > > Tim is of course 
> > absolutely right: REE's are not rare at all! > > They are rather 
> > abundant, though concentrated in economic > > quantities in 
> a limited 
> > number of deposits only. > > > > China seems to have most of the 
> > reserves, but the Mountain > > Pass deposit in California 
> is a major 
> > reserve base for the US.> > > > No, we won't run out of 
> REE's in ten 
> > years. It will take > > much, much longer, and before that we will 
> > have run out of > > many other elements.> > > > REE's are of 
> > strategical importance in numerous high-tech and > > defence 
> > applications. > > > > Also in our daily life we have become rather 
> > dependant on > > these phantastically interesting metals. 
> Especially 
> > in > > optical and magnetical applications they are of great 
> > importance.> > > > Yes, REE's are boring by appearance, and early 
> > scientists had > > good reasons to call them "rare earths". The 
> > mixtures of > > oxides early scientists managed to prepare were 
> > typically > > earth-like brownish.> > > > The pure oxides 
> of some are 
> > actually quite nice, cerium-oxide > > being nice yellowish and 
> > neodymium-oxide light pink. > > > > I guess modern purists would 
> > gladly get rid of such ancient > > terms like REE's and 
> would rather 
> > speak of the lanthanides, > > thereby excluding yttrium, and 
> > technically seen also lutetium.> > > > I am more a 
> romanticus and will 
> > always speak of the REE's and > > include yttrium and lutetium, and 
> > will even mention scandium > > as being rather close to the 
> family.> > 
> > > > Good samples of the classic REE's minerals -aeschynite, > > 
> > euxenite, fergusonite, polycrase etc.- from norwegian > > deposits 
> > have already become expensive and hard to find.> > > > 
> Samples of the 
> > REE-containing minerals that constitute > > present day ore 
> are as far 
> > as I know basically without any > > significance for collectors. I 
> > believe the Mountain Pass ore > > consists mainly of corns of 
> > bastnäsite. Anyone who has ever > > seen a good crystal, please DO 
> > correct me!> > > > Regards,> > > > Ronald Werner> > Norway> 
> > > > > > 
> > > > > > > > 
> > --------------------------------------------------------------> > 
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