massive crystals found in warwick new york

Two Glenn's in one forum. Thanks for the vote. We haven't really thought about a name. I guess we'll have to work on one. Any suggestions ?

Earl, I might have to bring this one with me when I visit Sterling Hill. Here are a few more pictures that might help



Edited 1 time(s). Last edit at 01/26/2011 12:46AM by Glenn Rhein.

Here is a large example of what Earl was speaking of-Tremolite in the Franklin marble.

Thanks David and Earl for the Tremolite lesson.

This is a cluster of weathered scapolite crystals off the wall. I cut a slice off with the wet saw expecting to see a nice red fluorescence under SW like the other scapolites we dug up but nothing. Hit the LW button and was surprised to see this.



Edited 1 time(s). Last edit at 01/26/2011 12:47AM by Glenn Rhein.

Hi Glenn, this should not be too surprising for meionite. Several finds of meionite over the years from the Limecrest Quarry in Sparta, NJ produced yellow and orange responses under UV light. Some very orange specimens were found that were translucent gray in daylight and a light or pale green color also tended to the orangy UV responses.
Steve.

Steve, what makes the same mineral give off different colors under UV

Meionite and titanite. This is a really nice piece



Edited 1 time(s). Last edit at 01/26/2011 12:48AM by Glenn Rhein.

Different trace impurities will cause different colours. I would love to know what causes the near blinding yellow fluorescence in some scapolites.



Edited 1 time(s). Last edit at 12/03/2010 10:44PM by Rob Woodside.

Rob , Does that mean Its not unusual to find different colors on the same mineral at the same location and does this apply to most or all minerals

A deformed or melted apitite



Edited 1 time(s). Last edit at 01/26/2011 12:48AM by Glenn Rhein.

Usually the material from a given location will behave the same and this applies to most minerals. However, Fluorescent localities, like Franklin and Greenland, can produce the same minerals with different fluorescences.

@ Rob: The almost-blinding yellow fluorescence seen in some scapolites is due to the disulfide ion as an impurity, substituting for the carbonate ion in the scapolite (meionite) crystal structure. The less-saturated yellow fl. of Glenn's scapolites does not look like the disulfide-activated scapolites I've seen, and I suspect is due to a different, as yet unknown, activator. Measurement of the emission spectrum of a local example would tell us that for sure, but might not be sufficient to determine the activator of fluorescence.

@Glenn: The deep red shortwave fluorescence you see in much of your scapolite is due to ferric iron substituting for calcium in the meionite structure. This same impurity, again substituting for calcium, is responsible for the deep red fluorescence seen in much plagioclase feldspar.

@ Glenn again: Normally a given mineral at a given locality will show only one color of fluorescence, but exceptions are numerous. Scapolite in the Franklin Marble is one of them. Different impurity elements, different colors of fluorescence -- we see this often. Your rocks up there have had 1.3 billion years to get "complicated", and they've done a good job of it. Any mineral that, once formed, becomes subject to alteration and/or recrystallization, or that forms during two or more different time periods, can show different colors of fluorescence because their chemical compositions are different.

Tremolite and norbergite in a nice pattern 5 by 6 inches



Edited 1 time(s). Last edit at 01/26/2011 12:49AM by Glenn Rhein.

Thanks Earl!!! Why does the disulfide emission have such a broad peak? Is the disulfide banging around in an over sized cage leading to a wide range of emission energies? Recently I joined the Fluorescent Mineral Society (http://uvminerals.org/fms/about-fluorescent-mineral-society ) and I'm thinking of getting a spectrophotometer to see the fluorescent wavelengths.

Rob- I am not nearly as conversant on this subject as I'd like to be, but if you look at the emission spectrum of a disulfide-activated mineral, what you see is a moderately broad peak with numerous subsidiary peaks superimposed upon it. Those smaller peaks reflect vibrational states of the disulfide ion.

Let's first consider a simpler case, a single ion in a crystallographic site -- say, divalent manganese substituting for calcium in calcite (which will then fluoresce red). At any temperature above absolute zero the ions in the crystal structure are vibrating, so any given crystallographic site does not have a fixed geometry, but "wiggles" a little. The metal (Mn in this case) to oxygen distances are constantly changing. Now, if you zap those Mn ions with ultraviolet light, at any given time the metal-to-oxygen distances for some ions will be at a minimum, for some a maximum, and for some intermediate. The wavelength of the visible light emitted from an excited state will vary according to the metal-to-oxygen distance at the time of emission. The result is an emission spectrum that shows not a line emission, but an emission peak of finite width. The width of the peak decreases as the temperature of the sample is lowered, which is why researchers commonly prefer to measure emission spectra at very low temperatures. The electronic transitions are much easier to "read" that way.

Now go to the more complicated case of an ionic group consisting of more than one atom -- in our case, the disulfide ion. Now you have two ions, the distance between which can vary between some minimum and maximum values. This introduces additional vibrational states, and because those states are quantized (there is not a continuum of "allowed" distances separating the ions, but discrete values), you will see multiple vibrational peaks superimposed on the main one in the fluorescence emission spectrum. That make sense?

This Scapolite (Meionite) cleaned up really well.



Edited 1 time(s). Last edit at 01/26/2011 12:50AM by Glenn Rhein.

Yes it does!!! Thanks so much Earl. I now understand why you guys are keen on low temp spectra.

What physicist take and teach from Einstein's 1905 paper ("photon paper') on the photoelectric effect is that the light energy depends on the wave's frequency and not just on the squared amplitude as explained by classical physics. That being the case there's lots of energy in short wave UV, more than in long wave, so short wave should produce all the fluorescent colours of long wave. WRONGO!!!! Not just energy conservation is important here, but also equally important is momentum conservation and this is where the different long and short wave responses arise. So I've gotten interested in just what the electron states look like.... Sorry for hijacking the thread.

[attachment 27229 austin055.JPG]Rob, I don't mind the hijacking I learn all kinds of things from this thread but I must admit some of it is way over my head.

My grandsons version of the fluorescent rocks. (Austen)



Edited 1 time(s). Last edit at 01/26/2011 12:50AM by Glenn Rhein.

Cool!!!

Your ¨deformed¨ apatite kinda resembles ones from bancroft that have a melted appearance. it sometimes seems like they have a cyclical growth and nothing grows in the middle. i really dont know if its a void sometimes or not. I could only assume it is.

could you take a foto of the tremolite and norbergite without the UV ? just curious how they look without it.

sad to know that its winter because your find has been great to watch i still cant wait for whats to come.

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A buena hambre no hay pan duro

The guys back east call these Calcite Vein Dike Occurrences and to their displeasure I call them carbonatites. They are almost frequent in the Grenville. However most are not as prolific as yours. See if you can get 2000 ppm Strontium in a bulk carbonate sample. If so you have a carbonatite.

that scapolite did clean up VERY nice glenn!
B)

Matt, here are some pictures of the Tremolite- Norbergite without UV



Edited 1 time(s). Last edit at 01/26/2011 12:52AM by Glenn Rhein.