I bought a cheap laser pointer from China (405 nm - violet) and have found several things that fluorese in this near UV light (ruby is one). I was checking some calcites from Jones Mill, Arkansas and found that they luminesced and phosphoresced a medium pink in the beam. A quick survey showed that most of the calcites from the alkali syenites showed this same response. Expanding the investigation I tried a variety of other calcite with little luck. Finally, I tried some slices of fluorescent calcite-willemite from Franklin, NJ. The calcite was mostly dead to the violet beam, but to my surprise, there were patches that showed the same pink response as the syenite calcites. Could this fluorescence be an activator like REE, and if so, why would small patches of it show up in the Franklin material? This has me puzzled, but until I can conduct some additional tests, I'm at a loss as to the origin of the fluorescence. Has anyone else observed this phenomenon? http://www.mindat.org/forum.php?read,100,174291,174291#msg-174291 Thu, 20 Jun 2013 03:33:24 +0000 Phorum 5.2.15a http://www.mindat.org/forum.php?read,100,174291,257565#msg-257565 http://www.mindat.org/forum.php?read,100,174291,257565#msg-257565 Henry Barwood Analytical Techniques Sun, 08 Apr 2012 00:25:41 +0000 http://www.mindat.org/forum.php?read,100,174291,257493#msg-257493 http://www.mindat.org/forum.php?read,100,174291,257493#msg-257493
Pink calcite from the Tankerville or Snailbeach mines in Shropshire (England) show a strong orange reaction with good persistence. If you are quick, you can almost write your name on a big chunk! Weardale fluorite works a treat, and so do most cerussites, Bage mine phosgenite and matlockite give good yellow responses. Anglesites from Broken Hill (NSW, Australia) or from Parys Mountain (Wales, UK) react quite strongly - those from Sardinia seem variable - some do; some don't, and Autunite nearly takes off on a beam of emitted photons!

There are lots of things I haven't tried yet, but that is a start...

Cheers

Tim]]> Timothy Greenland Analytical Techniques Sat, 07 Apr 2012 13:56:00 +0000 http://www.mindat.org/forum.php?read,100,174291,257459#msg-257459 http://www.mindat.org/forum.php?read,100,174291,257459#msg-257459 Frank K. Mazdab Analytical Techniques Sat, 07 Apr 2012 07:08:22 +0000 http://www.mindat.org/forum.php?read,100,174291,257414#msg-257414 http://www.mindat.org/forum.php?read,100,174291,257414#msg-257414 Henry Barwood Analytical Techniques Fri, 06 Apr 2012 20:00:25 +0000 http://www.mindat.org/forum.php?read,100,174291,257372#msg-257372 http://www.mindat.org/forum.php?read,100,174291,257372#msg-257372 Frank K. Mazdab Analytical Techniques Fri, 06 Apr 2012 09:39:49 +0000 http://www.mindat.org/forum.php?read,100,174291,256909#msg-256909 http://www.mindat.org/forum.php?read,100,174291,256909#msg-256909 Cheers! JerryBear]]> JerryBear Analytical Techniques Sun, 01 Apr 2012 21:42:09 +0000 http://www.mindat.org/forum.php?read,100,174291,201695#msg-201695 http://www.mindat.org/forum.php?read,100,174291,201695#msg-201695 Berthold Weber Analytical Techniques Tue, 09 Nov 2010 07:30:25 +0000 http://www.mindat.org/forum.php?read,100,174291,200163#msg-200163 http://www.mindat.org/forum.php?read,100,174291,200163#msg-200163 Donald Vaughn Analytical Techniques Sat, 23 Oct 2010 17:27:16 +0000 http://www.mindat.org/forum.php?read,100,174291,199917#msg-199917 http://www.mindat.org/forum.php?read,100,174291,199917#msg-199917 Henrik Friis Analytical Techniques Thu, 21 Oct 2010 18:05:42 +0000 http://www.mindat.org/forum.php?read,100,174291,199907#msg-199907 http://www.mindat.org/forum.php?read,100,174291,199907#msg-199907 I was still in the mineralogy mindset when I posted the comment about the usefulness.]]> Donald Vaughn Analytical Techniques Thu, 21 Oct 2010 16:48:48 +0000 http://www.mindat.org/forum.php?read,100,174291,199896#msg-199896 http://www.mindat.org/forum.php?read,100,174291,199896#msg-199896 Yes that is why many minerals will show the same luminescence, especially when you start exciting in the visible region. A lot of minerals have very broad excitation bands in the UV region, and as these can have a "tail" into the visible region your 405 nm laser might also these in addition to Sm³⁺. This might be the case of the calcite you mention.

And weather this has any usage or not, I believe it does. I think a lot can be learned, and new ideas created for the material science community, by looking at natural minerals. At the moment a lot of research focus on generating low energy consuming lighting in the form of LEDs, dosimetry badges or security marking all utilizing luminescence.]]> Henrik Friis Analytical Techniques Thu, 21 Oct 2010 15:34:05 +0000 http://www.mindat.org/forum.php?read,100,174291,199734#msg-199734 http://www.mindat.org/forum.php?read,100,174291,199734#msg-199734 Donald Vaughn Analytical Techniques Tue, 19 Oct 2010 16:01:55 +0000 http://www.mindat.org/forum.php?read,100,174291,199632#msg-199632 http://www.mindat.org/forum.php?read,100,174291,199632#msg-199632
Attached is a photoluminescence spectra of five different apatites I ran some years back with 405 nm excitation. The sample "DUR" is from Durango. The emissions are from Sm³⁺

Henrik]]> Henrik Friis Analytical Techniques Mon, 18 Oct 2010 07:03:40 +0000 http://www.mindat.org/forum.php?read,100,174291,199629#msg-199629 http://www.mindat.org/forum.php?read,100,174291,199629#msg-199629 Donald Vaughn Analytical Techniques Mon, 18 Oct 2010 04:14:08 +0000 http://www.mindat.org/forum.php?read,100,174291,199298#msg-199298 http://www.mindat.org/forum.php?read,100,174291,199298#msg-199298 405 nm is the strongest absorption band of Sm³⁺, which is a strong activator of photoluminescence (PL) in many minerals, e.g. apatite and leucophanite. Often minerals that shows Mn²⁺ luminescence with high-energy excitation (like cathodoluminescence) will actually have REE³⁺ activated luminescence in PL. So perhaps Sm can explain the emissions in some of the calcites.

Berthold,
That is an amazing picture

cheers

Henrik]]> Henrik Friis Analytical Techniques Thu, 14 Oct 2010 17:40:55 +0000 http://www.mindat.org/forum.php?read,100,174291,199289#msg-199289 http://www.mindat.org/forum.php?read,100,174291,199289#msg-199289 Berthold Weber Analytical Techniques Thu, 14 Oct 2010 16:28:12 +0000 http://www.mindat.org/forum.php?read,100,174291,199282#msg-199282 http://www.mindat.org/forum.php?read,100,174291,199282#msg-199282 1. massive pink calcite from Selleck road tremolite locale in St. lawrence co. has response, but none under lw UV. seems odd
2. Yellow Lake roadcut calcite St. lawrence co. New york really bright response, have not tested with lw UV.
3. Thompson-Mckulley qy. Michigan no response.
4. massive calcite from Herkimer New york no response.
5. several calcites from Lockport Formation no response.
6. massive Calcite from Douglas lake in Tennessee no Response to laser but really bright orange response to lw UV.
the first and the last are interesting to me since the responses to the laser and the UV are opposites seems counter intuitive]]> Donald Vaughn Analytical Techniques Thu, 14 Oct 2010 15:24:52 +0000 http://www.mindat.org/forum.php?read,100,174291,181914#msg-181914 http://www.mindat.org/forum.php?read,100,174291,181914#msg-181914 James Christopher Analytical Techniques Fri, 07 May 2010 00:39:10 +0000 http://www.mindat.org/forum.php?read,100,174291,178926#msg-178926 http://www.mindat.org/forum.php?read,100,174291,178926#msg-178926
I know there is a lot of variation in the Mn content of the calcite, I just never realized how patchy it is until I played around with the pointer.]]> Henry Barwood Analytical Techniques Mon, 12 Apr 2010 20:41:14 +0000 http://www.mindat.org/forum.php?read,100,174291,178923#msg-178923 http://www.mindat.org/forum.php?read,100,174291,178923#msg-178923
If the scattered light is a different hue than the pointer, then there is likely some fluorescent component. Simple scattering would not alter the hue unless there were selective absorption going on within the smithsonite. Now if the smithsonite is highly colored, that would be a different matter.]]> Henry Barwood Analytical Techniques Mon, 12 Apr 2010 20:35:59 +0000 http://www.mindat.org/forum.php?read,100,174291,178855#msg-178855 http://www.mindat.org/forum.php?read,100,174291,178855#msg-178855
My initial reaction was that the light was simply refracting within the specimens - they glow a very intense red/pink - sightly different to the laser red itself. Though this may simply be the fact that the laser is penetrating the translucent Smithsonite. Bit like a red light within an eggshell.

I don't think its fluorescence itself]]> Keith Compton Analytical Techniques Mon, 12 Apr 2010 13:11:40 +0000 http://www.mindat.org/forum.php?read,100,174291,178754#msg-178754 http://www.mindat.org/forum.php?read,100,174291,178754#msg-178754 Perhaps Dick Bostwick can give you a more detailed response. Hope this helps.
Steve.]]> Steven Kuitems Analytical Techniques Sun, 11 Apr 2010 18:31:27 +0000 http://www.mindat.org/forum.php?read,100,174291,178727#msg-178727 http://www.mindat.org/forum.php?read,100,174291,178727#msg-178727
Have you ever tried other wavelength pointers to see if a similar effect is noticible? Is the glow notably different in hue than the red laser?]]> Henry Barwood Analytical Techniques Sun, 11 Apr 2010 15:49:56 +0000 http://www.mindat.org/forum.php?read,100,174291,178693#msg-178693 http://www.mindat.org/forum.php?read,100,174291,178693#msg-178693
I have noted in the past that when a red laser pointer (the type used for lecture purposes) is directed at most Broken Hill (Australia) Smithsonites - particularly the rounded / globular form, that they literally glow a deep pink. Actually makes it easier to discern other asociated minerals that may be lurking on the specimens. I am not sure if this is a real fluoresecence because they don't fluoresce under the usual UV lights. It is as if the Smithsonite is reflecting the laser within itself. It doesn't have to be dark to see the effect - a typical room in softened daylight is ok.

Unfortunately I don't know enough about the physics of Fluorescence to explain what happens or why, or if in fact it is a form of fluorescence or luminescence.

Cheers]]> Keith Compton Analytical Techniques Sun, 11 Apr 2010 07:25:03 +0000 http://www.mindat.org/forum.php?read,100,174291,177911#msg-177911 http://www.mindat.org/forum.php?read,100,174291,177911#msg-177911 Divalent manganese, in concentrations of up to several percent, is responsible for the red or orange fluorescence of calcite, the green fluorescence of willemite, the yellow fluorescence of esperite, and the orange fluorescence of wollastonite and clinohedrite.
So maybe most Franklin Mn was bound up in the other minerals, leaving none or little for the calcite.
Furthermore, certain impurities such as iron or copper need to be absent, to prevent quenching of possible fluorescence.
Or maybe the calcite has quenchers such as those?

Divalent manganese, in concentrations of up to several percent, is responsible for the red or orange fluorescence of calcite, the green fluorescence of willemite, the yellow fluorescence of esperite, and the orange fluorescence of wollastonite and clinohedrite. Hexavalent uranium, in the form of the uranyl cation, fluoresces at all concentrations in a yellow green, and is the cause of fluorescence of minerals such as autunite or andersonite, and, at low concentration, is the cause of the fluorescence of such materials as some samples of hyalite opal. Trivalent chromium at low concentration is the source of the red fluorescence of ruby corundum. Divalent europium is the source of the blue fluorescence, when seen in the mineral fluorite. Trivalent lanthanoids such as terbium and dysprosium are the principal activators of the creamy yellow fluorescence exhibited by the yttrofluorite variety of the mineral fluorite, and contribute to the orange fluorescence of zircon. Powellite (calcium molybdate) and scheelite (calcium tungstate) fluoresce intrinsically in yellow and blue, respectively. When present together in solid solution, energy is transferred from the higher energy tungsten to the lower energy molybdenum, such that fairly low levels of molybdenum are sufficient to cause a yellow emission for scheelite, instead of blue. Low-iron sphalerite (zinc sulfide), fluoresces and phosphoresces in a range of colors, influenced by the presence of various trace impurities.

Crude oil (petroleum) fluoresces in a range of colors, from dull brown for heavy oils and tars through to bright yellowish and bluish white for very light oils and condensates. This phenomenon is used in oil exploration drilling to identify very small amounts of oil in drill cuttings and core samples.]]> James Christopher Analytical Techniques Sun, 04 Apr 2010 14:56:39 +0000 http://www.mindat.org/forum.php?read,100,174291,175519#msg-175519 http://www.mindat.org/forum.php?read,100,174291,175519#msg-175519
John Attard

San Diego.]]> John Attard Analytical Techniques Sun, 14 Mar 2010 01:02:47 +0000 http://www.mindat.org/forum.php?read,100,174291,174400#msg-174400 http://www.mindat.org/forum.php?read,100,174291,174400#msg-174400
OK, didn't read your post about the Terlingua clacite well enough. I also discovered that some intensely SW fluorescent yellow fluorites from Bedford, Indiana also luminesce brilliantly with the 405 nm laser.I also located a box of Franklin slices and checked more calcite. The response varies from nil to fairly intense pink-orange.]]> Henry Barwood Analytical Techniques Fri, 05 Mar 2010 03:19:58 +0000 http://www.mindat.org/forum.php?read,100,174291,174390#msg-174390 http://www.mindat.org/forum.php?read,100,174291,174390#msg-174390 It also looks like my XRF will finally happen!]]> James Christopher Analytical Techniques Fri, 05 Mar 2010 01:25:44 +0000 http://www.mindat.org/forum.php?read,100,174291,174376#msg-174376 http://www.mindat.org/forum.php?read,100,174291,174376#msg-174376
Fascinating. I'm very curious why there are isolated activated domains in the Franklin calcites. There is obviously something odd going on. I checked a few Indiana calcites and found very little response in them. I'm glad to know that the Terlingua calcites have low response levels. I was going to see if I had a piece I could check. The plaster could be from an organic additive. Most plastics and many organic chemicals I've checked have moderately strong responses at 405 nm.]]> Henry Barwood Analytical Techniques Thu, 04 Mar 2010 22:04:46 +0000 http://www.mindat.org/forum.php?read,100,174291,174302#msg-174302 http://www.mindat.org/forum.php?read,100,174291,174302#msg-174302 A little off subject, but I found plaster on the walls and ceiling has a short phosphorescence in a dark room with the laser.]]> James Christopher Analytical Techniques Thu, 04 Mar 2010 04:52:10 +0000