top of page

"Black Rose" Fluorite - Fluorescence will ultimately fade to a dim blue after long exposure to LW.

There have been several posts i our FB group lately about this fluorite listed on eBay as "Black Rose" from China sellers. Specific locale unknown. The pictures seemed unbelievable so I had to get one for myself to see.

They are kind of believable, for a little while. Shown under 365nm LW, SW, and white light, dollar for scale. I was thinking the crystals covering the fluorite are calcite but now question, haven't done any testing yet. The LW pic was taken with high power LEDs, and fresh after being recharged (see below).

Interesting on this piece are veins of blue within the broken matrix. Like Mapami fluorite, long exposure to LW UV causes the red to fade. But exposing it to SW UV "recharges" it back to its original brightness, but seems that eventually this recharging will no longer work. I find the velvety red color quite attractive. Not the brightest guy on the block, but respectable.


But - check the comparison image, comparing the rock after multiple lengths of time under LW and SW:

The comparison image below shows the various states after long exposure to 365nm LEDs. After 24 hours of exposure to very powerful LW 365nm LEDs the piece has turned almost completely blue except for a couple of very stubborn spots of dim red. Attempting to "recharge" with SW for 24 hours only resulted in some areas returning to the red color, with a much dimmer response. I broke this rock.


A COUPLE OF QUESTIONS ABOUT THIS MATERIAL NEED TO BE ANSWERED:
  • Anybody have reliable information on the locality?

  • There have been several comments saying that these pieces have been irradiated. Has anyone confirmed this, and if so, how? Based on my tests and comments in our FB group, it seems that these pieces are irradiated.

(BTW - I bought this on eBay. Seller had it listed for $360, I offered $100. He accepted. Don't be hesitant to make a low offer, especially on specimens from China.)


Chris Clemens added this comment on FB:

"Chris Clemens Mark, you make a very pertinent comment about these "black rose" fluorites as being "Not the brightest guy on the block." Not surprisingly, they don't live up to the expectation that the buyer may have for them based on the listing photos posted by the Chinese seller(s). A velvety red response can clearly be seen under LW UV, but it doesn't come close to what is falsely portrayed in the listing photos (which are dramatically overexposed), which might lead one to believe that these specimens show an intense red response. I too couldn't resist checking one of these out and was somewhat underwhelmed by it, even after charging it up for 30 minutes under SW UV. They definitely display best under the high output beam of a Convoy C8 or similar LW UV source. I would rank the brightness of the response as well below my better pieces from Mapimi, Cave-In-Rock, and Morocco. I think you did a great job of accurately portraying the intensity/brightness of the response in your photos above. I agree with Glenn's earlier comment that the red fluorescence, as well as the dark purple/black daylight color of these specimens, is due to irradiation, by either natural or laboratory exposure, and the subsequent creation of lattice defects.


Glenn Waychunas added this comment:

Glenn Waychunas The mechanism for "recovery" is different if the M-centers are made mainly from radiation. M-centers are not very stable. There may be some recovery with time. If I can get my act together Howie will get a Waves article from me on the whole issue.






After 6 hours of continuous exposure to LW UV I took another pic. Here's another interesting datapoint. Left the rock under LW UV for about 6 hours. Pic below shows significant dimming of the red, *except* on the bottom. The blue vein has increased in size. Exact same camera settings, just left everything on.





Next going to recharge it with SW just to show it returns to original colors.

682 views0 comments

Comments


bottom of page