Very Strong Green Fluorescence.

[Richard Sherwood]

-----------
Careful microscopic inspection seems to indicate that the green
fluorescence is coming from microscopic bubbles in the stone. Not the
micro solid inclusions that is usually associated with clouds. These
bubbles could be just air bubbles or perhaps some form of fluorescing
gas.
-----------

They couldn't be air bubbles or gas, as these inclusions aren't found in diamond due to the nature of its crystallizaton. All air and gas escapes the host as it is crystallizing under intense heat and pressure. They have to be something else. It would be interesting to know what.

 

[questionsRus]

kryptonite?

 

[jenwill]

That was hilarious!

 

[mdx]

----------------
On 8/3/2004 8:22:09 PM Richard Sherwood wrote:

-----------
Careful microscopic inspection seems to indicate that the green
fluorescence is coming from microscopic bubbles in the stone. Not the
micro solid inclusions that is usually associated with clouds. These
bubbles could be just air bubbles or perhaps some form of fluorescing
gas.
-----------

They couldn't be air bubbles or gas, as these inclusions aren't found in diamond due to the nature of its crystallizaton. All air and gas escapes the host as it is crystallizing under intense heat and pressure. They have to be something else. It would be interesting to know what.

----------------

Richard what I am thinking of is ultra high pressure inclusions in the form of deep mantle methane trapped in the crystal.

Johan

 

[CaptAubrey]

gas and fluid inclusions in diamond have been documented, though they are quite rare. they are believed to result from organic material drawn into the mantle by subduction of continental crust. the carbon in these types of diamonds has a similar organic source. there is much acrimonious debate in the scientific community over these issues, but that's the general theory.

 

[wanderlost]

the Study of Inclusions..... (info gleaned from a PBS special that I saw a few days ago that I wonder if anyone else saw)....

Diamonds themselves are not able to be carbon-dated.... therefore the study of included diamonds (and the inclusions themselves here) point to a [questionable IMHO] date of ~3.5 billion years old. Inclusions are primarily studies with X-ray (specs?) and there's little information (public) yet...

Does anyone else think that this would be absolutely facinating? Oh... and they mentioned a few of the more common 'pigments' sources (if I can remember them correctly) - Boron = Blue.... Yellow = Sulfur or Nitrogen (i think)... Green = Carbon (different structure?)

The thing that I don't understand with the fluor & phosphor is what element is in there that is allowing electrons to reach a higher state and then release - when this is supposed to be a solid crystal lattice....

please correct me if I'm wrong on anything here....

 

[CaptAubrey]

----------------
On 8/4/2004 2:12:11 PM wanderlost wrote:





The thing that I don't understand with the fluor & phosphor is what element is in there that is allowing electrons to reach a higher state and then release - when this is supposed to be a solid crystal lattice....

----------------

except that it's not a solid crystal lattice. there are all sorts of impurities, lattice defects, and vacancies that can cause color. blue fluorescence is caused by nitrogen substituting for carbon in the lattice (known as the n3 center, since it's a group of three nitrogen atoms). other types of nitrogen defects cause other colors of fluorescence.




diamond can be dated by their inclusions, usually garnet, clinopyroxene, and zircon. zircon often contains uranium, which is very useful for isotopic dating. the median age of diamonds is thought to be around 1 billion years, give or take.




nitrogen is the cause of yellow, and boron is the cause of blue (in most cases). green is caused by radiation damage.

 

[wanderlost]

Maybe someone else can chime in on this as I'm more than a bit confused....

the aforementioned "radiation damage" both now & in the green diamonds thread doesn't quite add up to me.... I can understand the "bubble like inclusions" as mentioned as a part of the formation of the diamond.... but if you had a normal stone and exposed it to radiation (from Ra, U, Pu, etc).... I don't understand how an alpha or beta particle could cause changes whatsoever to the crystal structure (especially to a non-surface bond or atom).... leaving only gamma radiation as the source of the changes.

(to further the previous point, Alpha radiation (essentially a He atom being ejected from a nuclei) due to its size (and relative low energy) cannot move more than a few inches in air or pass through a thin barrier such as a sheet of paper... Beta, smaller & higher energy, could be an explanation, however both Radium (228 I believe) and most states of Uranium are alpha emitters. Finally, with gamma.... there's always gamma around us - through the roof, down into the ground (largest source is the sun) and I don't believe (though in a few million years, I could be disproved) that all diamonds are heading in the green direction.... not to mention, I can't rectify why I 'solid' crystal could/would incorporate some piece of Radium (internally?!) to cause it to still be 'hot' today......)

again, thanks for any info you might have.....

 

[CaptAubrey]

----------------
On 8/4/2004 5:07:12 PM wanderlost wrote:





Maybe someone else can chime in on this as I'm more than a bit confused....

----------------

not to worry, as this is a pretty technical subject.

most natural radiation that diamonds are exposed to, as you note, is alpha, which is why most natural "green" diamonds actually have only a shallow green "skin" (or small spots often called radiation "stains"). diamonds with a saturated green body color going all the way through are very, very rare. they occur only when the diamond has lain next to a high energy gamma source for a long time--obviously not a common occurrence.

however, creating green diamonds in a lab is fairly easy--most are either irradiated in a reactor (gamma/neutron) or in a linear accelerator (electrons). early diamond irradiation was performed with radium, but this left the diamonds highly radioactive, since the decay products were implanted in the lattice (not the radium itself).

irradiation of diamond creates a vacancy in the crystal lattice by moving a carbon atom out of its normal spot. this is known as the gr1 center, and it absorbs in the red-orange region of the spectrum, creating the green color. heating green diamonds gradually repairs the damage, creating other colors or restoring the original color (if heated long enough).

note that this is not the same as green fluorescence--that has an entirely different cause.

 

[wanderlost]

CaptAubrey
thank you very much for your knowledge