Tucson 2021 – Benitoite

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November 17, 2019

The Fluorescent Mineral Society is putting together for Tucson 2021 what might be the largest display of fluorescent minerals ever seen. Al Liebetrau, George Polman, and Conrad North are among dozens of FMS members who have been working tirelessly at bringing this vision to life.

The Tucson Gem and Mineral Society announced over a year ago that the Big Show’s 2021 theme would be fluorescent minerals and the race to pull off a world class display has been on ever since. The buzz for Tucson 2021 continues to grow. (internal link).

I’m coordinating a benitoite display case for the exhibit. This page will record those developments. Please contact me if you have any material to loan or a piece you think I might want to buy. I’m especially interested in larger material and any stones that exhibit red fluorescence.




The 2021 TGMS Show will run from February 11th through the 14th.

More details to follow with pictures and links and all that.

Thanks in advance, Thomas

Planning on Tucson either this year or 2021? Prepare for traffic, parking, and getting around the city.  I describe here what I found three years ago. (internal link).

November 19, 2019

Ordered a vial of rough looking benitoite crystals, none of them well terminated. 50 carats or fifty small pieces. Why? As a group they may present an interesting display. I have a vial of zircon sand from Australia whose grains  light up a wonderful yellow under SW.  Arranged on a black plate they make an arresting sight. There might be a way to show off these small benitiote pieces as a contrast to the larger individual specimens in the case. We’ll see.

Crystals came from The Capistrano Mining Company:













November 22, 2019

Ordered my first large specimen for the benitoite display from Kevin Brady’s store on eBay. I wouldn’t normally buy something at this price without seeing it first in person but Brady has been an FMS member for almost 40 years and knows Al Liebetrau who is advising me on coordinating the case. I will take photographs when I get it. This benitoite specimen was bought first for its UV display, not its esthetic qualities in visible light.

Kevin Brady’s eBay store is here:


November 23, 2019

Benitoite crystals arrived today and they are glowing as I had hoped, with a variability that I will have fun learning about. Benitoite shows a wonderful powder blue under SW but I had heard about some red florescence. By getting a large number of pieces, although small, I am better able to look for this occasional occurrence and research same.

These are horrible handheld iPhone pictures taken in a barely dark room. I will eventually get my full frame sensor Nikon D90 on a tripod at night and then reshoot. I am having good luck at eliminating blue bleed at 15,000 Kelvin, an aspect of white balance. It will probably take a half hour to set up the camera, an odious chore as I am not a professional. Never-the-less, these crude photos show what I will investigate.

Unprocessed closeup photo taken with my Nikon D90. From a distance they are much fainter. The crystals in their bowl are picking up dust and I need to quiet the background.

November 27, 2019

Kevin Brady’s piece arrived the other day and I am eager to show it in its best light. Pun intended. I intend to carry out a long desired experiment, to take pictures under the same conditions with a film camera and a modern day digital camera. This will probably burn up an entire weekend to complete so it is just a matter of time, not of getting more equipment.

Right now I spend a tremendous amount of time setting up my digital camera. It means getting the right angle to shoot from, adjusting the tripod, fussing with white balance, remembering how to turn on the camera’s timer to reduce shake, and so on. And all of this is followed with much time in post, using Adobe CC’s built in camera RAW software. I have dabbled using Lightroom as well. Maybe I can reduce the time in post with film.

I’ll be using Kodak Extachrome 100 in a used Nikon film camera I got off of eBay. Dead light meter, manual focus, but that’s fine. The lab will provide me with high resolution digital files. I’m eager to see what an analog camera captures compared with a digital camera’s sensor. I suspect a digital sensor has inherent problems with UV subjects but I could be wrong.

As these handheld iPhone pictures attest, the specimen Brady provided is quite wonderful but I need to take better pictures. I am going to suggest the FMS hold a UV photography class at Tucson 2021. As a last comment, the piece displayed no red florescence.

Ordered another vial of crystals to have more material to experiment with.

November 29, 2019

Ordered two back issues of the Mineralogical Record that deal with benitoite.

Sent an e-mail to Kerry Day for advice on how to test for what I suspect is the element or elements causing the red florescence in certain benitoite pieces. Day performs qualitative EDS analysis to identify minerals. Since the mineral here is already identified, my guess is that I am looking for a trace element, not a mineral. XRF analysis may be the right choice and I have previously used Express XRF out of Bozeman, Montana. Rather than guess at the right testing method, I will rely on Day’s advice. I have sent him many mystery minerals for testing and his analysis always proves sound.

Kerry Day’s website is http://www.kaygeedeeminerals.com/

His etsy store is here:


His selection of minerals and rocks, by the way, is wonderful. Inquire if you don’t see something you are searching for. I have bought many things from him.

November 30, 2019

Kerry Day said he’d try to find out what he could with his equipment. So this morning I sent off a blue, white, and clear crystal for his analysis.  But no less a source than Wikipedia weighs in on the matter.

“Benitoite fluoresces under short wave ultraviolet light, appearing bright blue to bluish white in color. The more rarely seen clear to white benitoite crystals fluoresce red under long-wave UV light.” Ah, ha! Who needs to wait for the Mineralogical Record when you can go to Wikipedia? (That is a joke, of course.) No reference cited, of course, but both Wikipedia and web mineral.com say that benitoite steaks white. I tested a white and clear crystal on a black steak plate just now and they indeed streaked white. Great.

I’m again interested in the difference in fluorescence and I am am eager to get Kerry day’s results. My crystals respond better to MW than LW. Although the digital camera needs setting up, I may soon post some microscope photographs of the different crystals I have. The scope is far easier to take pictures with than my Nikon.

December 2, 2019

Microscope photography didn’t provide the results I wanted with the time I had to give. Another day.

I’ve been in correspondence with Al Liebetrau of the FMS. He is managing all aspects of the display cases FMS will present at The Big Show. He’s suggesting a 30″ case for the benitoite and we have been discussing lamps.

Another specimen arrived today, large but not very presentable. Only a few spots of blue under UV. Since it has so little now, and because I paid very little for it, I am going to attempt to etch it with muriatic acid. I want to see if doing so reveals any more benitoite. I am particularly interested in the lumpy area on the back. This process may take weeks as I am learning as I go.

Benitoite etching experiment from Thomas Farley on Vimeo.


Benitoite lump now sitting in a bath of HCI and water. I will attend to it every hour or so for the first few hours, seeing what develops. I am following instructions, for the most part, from The Capistrano Mining Company’s page on etching benitoite:


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