FMF - Friends of Minerals Forum, discussion and message board

[Jordi Fabre]

Gail assumed in a recent post ( https://www.mineral-forum.com/message-board/viewtopic.php?p=5957#5957 ) that not all colored topazes lose their color with the sunlight.

I believe that all topazes are, more or less, sensitive to the sunlight. Could someone confirm or deny this?.

Jordi

[alfredo]

I agree with Jordi that most (all?) colored topaz is light-sensitive and likely to lose its color when exposed for a long time. But I've heard that some topaz is stable, so Gail might be right, although I would hesitate to put any nice colored topaz under a really bright light. Sometimes a dimly lit case might be best.

[strahler]

Jordi,

I have never seen a sherry colored topaz not fade. Having collected these at many locations, I have yet to see a color stable sherry piece.

Now, with that being said, I have seen several instances of color stable topaz. I have also seen color shifting in topaz.

The first instance is topaz from Colorado. Having collected many of these, both bi-colors(blue/sherry) and sherry, I have seen a unique shift in color. Upon leaving the bi-colors out in the sun, the sherry fades and the blue is left. Some sherry crystals, when exposed to the sun, the sherry fades out and the crystal turns blue.

Another unique location, I have collected, is a site on the East side of the Thomas Range in Utah. This location has an amazing shift in color, with the end color being stable, at least in my tests. The crystals start out as sherry, upon leaving them in the sun for one to three weeks, these crystals turn pink. Most sherry crystals in the Thomas Range turn clear, not these. Due to an unusually high pseudobrokite inclusion content in the crystal, they turn pink. The pink is stable, at least after one year of leaving these in the sun.

When I lived in Southern California and collected with Louis Spaulding at the Little Three Mine, we saw another neat color shift. Topaz that were collected as clear, when exposed to the sun, they turned blue. Also, blue crystals that came out of the 1976 and 1991 pockets, actually became much more blue with exposure. The blue crystals I have collected, and left out, are still blue to this day.

Now, I am not a geo-chemist or such( just a field collector with lots of exposure), so I cannot explain these occurances. I know this happens in other crystals, as well, morganites for instance. When we used to collect Morganites at various Southern California Pegmatites, we would leave them in the sun, this would "bring the pink up" in them.

Well, I hope this helps.

[Gail]

As always I never like to put any mineral in bright light for long, just a good practice to have. We keep many minerals, such as Proustite, covered when not displaying.
This pink topaz has held its colour nicely, and with the huge amount of collectors and dealers that come through our home, we have been told that it won't likely be one that will fade. I am not willing to test that theory, per se, but don't make a practice to cover it up either.
We only put the lights on when we have company or when I am enjoying a quiet moment to look at our pieces.

I am just going by what the "experts" say, and they say the pink topaz on matrix in our collection is not likely to fade.

[Tobi]

I don't think that ALL topazes lose their colour: There is a specimen from Mexico ( https://www.mindat.org/gallery.php?loc=5935 ) in my collection, which is on display for a decade or even more and it never lost any of its colour ...

[garchin]

Really? I am amazed! I have always thought Mexican Topaz will fade in sun, especially the wine red colour you are showing.

[Tobi]

No, not at all. The colour is still the same as it was when this topaz came to my collection, and this is - as i said before - more than a decade ago ...

[Ed Huskinson]

Hi Gail!! Thanks for sharing what you and Jim are having to do to prepare for the show. 53 cases, is it? If I had to fill 53 cases, I'd have to call in a cement truck for about 40 of them.... Anyway, now we all have a sense of what-all goes into an undertaking of this magnitude.

I've been away from my computer for the past week or so, unable to respond to posts. I hope the Fourth was with you, and with Jim as well.

With regard to the question of photosensitivity of certain minerals, I wish to weigh in. I simply consider ALL minerals to be light sensitive. That way, there's no finding out the hard way. In other words, I'm with you: "unwilling to test that theory" (re photosensitivity), regardless of who espouses whichever side. We are stewards of these precious objects, and to have people of a later generation say "Oops, he allowed his (fill in the mineralogical blank here) to sit in the sun, and it changed color.", well, that would just not be the right thing to have happened, eh?

I treat them all with equal respect. To that end, our mineral room has a single window, and that window is covered with heavy duty aluminum foil, and that foil is taped in place with heavy duty aluminum tape. The room is light-proof, and it stays that way sometimes for weeks on end, depending on how long the drill campaign or exploration program will take, and therefore how long I will be away from home. When I'm home, I go in every night to say goodnight and to lower my blood pressure. It's what I do.

Aleta made an observation though. She said "Ed, you know that if the police happen to drive by and see that this room has the window covered with aluminum foil, they're going to think that you're growing marijuana in there." I hadn't considered that possibility at all. But should they come a'knockin', I'll just let them in and explain about how the specimens are light-sensitive. It's either that, or dig a basement and install a vault, eh?

I started to say something back when you guys were talking about the green octahedral fluorite from Maine or Massachusetts, wherever. I know for a fact that fluorites are particularly sensitive to light, and should have warned you. I keep my Blue Blanchard Mine Beauties (how onomatopoetic!) in boxes.

Anyway, please keep the posts coming. It's so wonderful to be able to participate in the show vicariously through your efforts. Keep up the good work!

Ed

[Gail]

Ed, I have been fond of you for some time and reaffirm my reasons for being so again!
You are a true diplomat.
Yes, we are diligent in our work on the 53 cases. Two people, with very different experiences of display have to work together to come up with 53 cases...and believe it or not, we really had a lot more ideas than 53!
I will have an artistic case, which will be very fun. I am also adding my own touch with some jewelry and doo-dads ( American slang for "stuff" )
Jim likes to fill a case, I am a little more minimalist. But we agree to work together to make our cases as pleasurable to view for everyone as possible.
We see our minerals every day, but when you think of showing them for the first time it gives you a renewed passion for them. This truly IS fun, in a masochistic sort of way! ha ha.
Cheers!

[Matt_Zukowski]

Speaking of aluminum foil on windows, and being up here in the land of the midnight sun, I have foil on the windows of the master bedroom. It is the only way i can get a good night sleep this time of year.

[nurbo]

Hello,
Just a thought I had today after reading this thread:
Photosensitivity of minerals is not my strong point but is it possible that a portion of colour loss may not be down to light exposure but to the heat generated by the light? It may explain why some have faded and others havent, if your Topaz is in the sunlight in Karachi its going to be very hot whereas if your in Alaska its going to be really cold, Its well documentad that baked Amethyst is passed off as Citrine, or maybe each element heat and light have a proportional effect.
I have a small cluster that I was sold as Phenakite but it has red edges, John White kindly pointed out that it looked like Topaz and with a little artistic help from Parfaitlumiere Im now convinced its a Topaz, its on my collection thread . It has red edges and they are still is as red as when I got it, where I live its never more than about 25-28 degrees on my shelves, but also it only gets the early morning sun where it is maybe 15 - 18 degrees maximum.
Im going to research this theory with some purple/Green Mexican Fluorite which is reputed to turn red in sunlight, Im going to heat one slice and leave another in the sun and see what happens.
db

[Ed Huskinson]

Gail's GeeGaw's

The Spann's Spotlight Specials

Jim 'n Gail's Jewels

Kitsch by Bikin

Ahh, I don't know, these are just a few things that might work for your doodad case. It's pretty hard to beat Gail's Geegaws though....

I envy you guys the time and energy you are pouring into your passion. My days are filled with the ennui of mineral exploration, but hey, I'm working at what I love to do, so.

I'm more like Jim. Ask Les. He's the one who informally awarded me the "Shoehorn Trophy" one year. There was like, 5 mm of space between each specimen and a slightly lesser amount between labels. The more the merrier I'm thinking, but when you can't even tell for sure what color the liner is?? That's bad, eh?

Send us some photos of how it's coming along. At least I can look at a few rocks by checking my e-mail each night before I hit the hay.

Have fun!

Ed

[Ed Huskinson]

Hey Nurbo!!!

If you're going to experiment, then you need to set up a control. Two ways to go:

First, post a photograph of your red-tinged specimen now. A recent photo taken under controlled light conditions. We can thus compare with later postings over the months/years to come.

Second, do the same with your variegated fluorite. That should fade fairly quickly, and results should become evident in relatively short order.

This'll be fun!

OK, we're all happy to help out here, we just need to see what the specimens look like right now, as a literal "before" to compare to the "after" of light exposure and/or heat exposure.

Thanks,

Ed

[nurbo]

Hi Ed,
I'll design some kind of experiment covering all the permutations involved, it will be interesting to see the outcome, the Fluorite is massive vein Fluorite, the supplier says its from Mina le Navidad, Durango, Mexico. I'll post this as a new thread I think, soon as Ive done the cutting and polishing.
This will indeed be fun its been 10 years since I last designed an experiment (That was involving mineral residue's in local tap water compared to bottled water, I havent drunk tap water since)
.I'll try and find a cheap rough chunk of pink Topaz to include as well, I need a dinged rough not worthy of putting in my collection chunk ...... I wonder where I could find such a thing ..... sounds like a visit to ebay is in order

[Jason]

Wouldn't it all depend on the electron valence?

[nurbo]

Hi Amethystguy,
If memory serves electron valence is about having an electron or electrons in the outer shell of an atom that can be shared or even stolen by another atom, that would make a lot of sense as an explanation as to how the colour shift occurs, it seems to me it may also point to the catalyst for the reaction being heat and not light. The heat adding energy to the system causing the electron orbits to increase and that increasing the likelihood of an ionic bond being formed with another atom.
Though I might be completely wrong, its been a long time since I studied any chemistry. Im absolutely sure theres someone here who can help out with a better explanation of this than me.

[Jason]

I may be way off also but hey..can't hurt to try...It might be similar to amethyst(go figure) when in ground radiation causes the electrons to jump from +3 valence to +4 ,in turn giving it it's purple color but when left in the sun most amethyst will fade as their +4 electrons covert back to +3..this is all off the top of my head as i have read about it before and may be way off..has something to do with the UV rays? maybe?

[nurbo]

Thanks amethystguy youve given me another idea for the experiment, keeping three pieces in the dark and exposing one to LW UV one to to SW UVand the other to both to see what impact that has on the colour change properties. I have been thinking about the possibility of colour change being down to wavelengths of light, I have a Sodium light (The kind used to illuminate public buildings at night) which I may yet incorporate into this, there are a lot of permutations presenting themselves here, I hope Ive got enough Fluorite to cover them all.

[Tracy]

Hi Nurbo -

If you can use pieces from my Westmoreland fluorite that I intend to test my trimming skills on this summer, let me know and I'll gladly send some chunks with color (a lot of it is washed out, but there are still some colorful places), if I have any woth using, to help with your experiment...

- Tracy

[Peter]

I can confirm similar experience as Ryan B/ Strahler.
Most champagne colored topaz fade upon long sun exposure.
One pocket in the Kazionnitsa Pegmatite, Alabashka Pegmatite field, Urals faded after some years in non direct sunlight. Other pockets in thei pegmatite produced blue topaz.
Blue topaz from a nearby pegmatite, the famous Mokrusha vein topaz occurs as light blue, almost colorless to deep blue crystals. Some of these have a light champagne color in the core and near the termination which fades upon light exposure and seem to become light blue with time. The blue color in topaz from this pegmatite also seem to be intensified by light exposure. Topaz from Shigar, Braldu and Haramosh areas of N Pakistan of light to dark champagne to almost orange color (not the irradiated orange-brown) fade with exposure for sure and from some pegmatites rather rapidly.
Ukraininan (Volodarsk/Volhynsk) is usually a very dark orange incredible color when found in the pocket. Even small shards are brightly colored and fade rather quickly in bright sunlight. The bicolored samples found in some pockets *light pinkish champagne and blue) seem to be more stable (at least for 15 years).
Peter