FMF - Friends of Minerals Forum, discussion and message board

[Bob Carnein]

This is a question for those of you who are from Spain or like Spanish minerals. I recently saw a red-fluorescing fluorite for sale, labeled "Berbes, Spain". The fluorescence is very similar to that of the better known Ojuela mine fluorites. Because red-fluorescing fluorite is so rare, and because I had never before seen a specimen from Berbes, I wondered whether this is a familiar find that I just had not encountered before, or whether this specimen might be mis-labeled.

[Jesse Fisher]

I have a good number of Spanish fluorites from Asturias in our collection, and the only ones that show any fluorescence are a couple of yellow fluorites from the Moscona and Villabona mines. The color under LWUV is a pale fleshy pink, nothing that I would call "red" and certainly nothing like the Mina Ojuela fluorite. All the Berbes area fluorites that I have show no fluorescence at all. Do you have a photo of the specimen?

[monicaiRocks]

I can't think of any I've seen off the top of my head, but there's an article on chicagorocks dot org by Robert Beadle that says....


Red fluorescence in fluorite is equally as rare as yellow. I know of only seven locations with fluorite that fluoresces red. Perhaps the most well known of these is Berber Asturias, Spain. The purple-violet cubes from this region glow cherry red upon exposure to long wave ultraviolet light.(1, 9) Red fluorescence in fluorite has also been reported from Celles, in the Namur province of Belgium.(11) A specimen of "Blue John", a type of banded fluorite from England, has exhibited a zone of red fluorescence. The location given was Treak Cliff near the Odin mine in Castletown, Derbyshire.(10) Mexico has three locations for this rare occurrence — Sonora,(4, 13) Ojuela mine in Mapini, Durango(14) and Mina El Tule Melchor Muzquiz, Coahuila.(9, 10) But of these fluorites, only a small percentage fluoresce blue, and an even smaller percentage fluoresce red. Our United States has two locations for red fluorescence in fluorite. The Burney mine in the Chinati mountains in Presidio Co., Texas has produced at least one specimen.(12) The other location is the Griffith mine in Harden Co., Illinois. Specimens from there may be non-fluorescent, blue fluorescent, red fluorescent, or even yellow with red fluorescent. It has been suspected that the rare earth elements europium along with samarium are responsible for red fluorescence. For the Griffith mine, iron dissolved in oil along with europium may be the cause.(15)



(I have very different opinions on which is the most well-known, but that's neither here nor there...)

Did see one on Minerain with what I would call more pink than red (if we're thinking of "Ojuela red" as comparison) and there are some on eBay, but it's a much pinker/purplier, murkier hue.

[Bob Carnein]

I have attached a photo from the seller, who is on eBay. Of course, I have no idea how accurate the intensity or the color is. The specimen sold while I dithered about buying it (?!)
Yes, I've seen the specimens on eBay for sale by minerain, and those are nowhere nearly as intensely colored as this one.

[Jordi Fabre]

Yes, is relatively known from the area of Berbes named "Los Cobayos" (aka "La Paredona") but in all the ones I've seen the color is a kind of pale red, not intense red.

[Paul Bordovsky]

The deeper red color may be a result of the light source. LW 365 presumes one of the Convoy or Fyrefly flashlights with the LED chip. The reflector in these type of lights highly focuses the beam and makes the color more intense. I have no experience with the Berbes Fluorites, but the intensity of the Mexican Fluorites is enhanced. On Bob's posted specimen notice how the large cube is intensely colored, but the cubes on the periphery are much less intense. Here is one of my specimens.

[Josele]

Berbes sample with a moderated blue fluorescence concentrated at the edges and a slight red fluorescence in some interior layers: