Do Colombian Emeralds Flouresce Red under UV Light?

[gromit]

Hoping someone can help/clarify.

Have been trying to find out but getting contradictory information. Some say they flouresce red due to the chromium content (particular to origin) and others say to run the other way as it indicates it's a synthetic. Does anyone know?

Thanks in advance.

 

[RockHugger]

Means it's a synthetic in most cases.

 

[T L]

Some have weak red fluorescence due to chromium. If it glows super red, it may be a synthetic because synthetic emeralds are highly chromium rich.

 

[LD]

You may see a faint weak pink fluoresence as TL has said. Red? No.

Excuse the rubbish picture. On the left is an Alexandrite - strong fluor. On the right is the Emerald - weak fluor.

 

[gromit]

You may see a faint weak pink fluoresence as TL has said. Red? No.

Excuse the rubbish picture. On the left is an Alexandrite - strong fluor. On the right is the Emerald - weak fluor.

Came across this from Geohavens website on emeralds: http://www.geohavens.com/articles.php?article_id=68

"The Colombian emerald is blessed with a chemistry of color that is near perfect: mainly chromium, a little of vanadium and very little or no iron. It is the chromium that gives the green color as well as the red fluorescence. Vanadium creates the green emerald color but without the red fluorescence. Iron atoms in the emerald will blunt the red fluorescence and also make the green less pleasing by adding yellowish or bluish where it is not needed."

and also from 'Emeralds, A Passionate Guide", Chapter 12, http://www.emeraldpassion.com/sample.htm

"Colombian emeralds have not only fine color but natural fluorescence and microscopic inclusions whose presence reduces extinction."

That's why I am confused.

This website also has a very good picture of an emerald under the Chelsea Filter. Does look more pink than red. http://www.yourgemologist.com/ChelseaFilter/index.html


By the way...is this the emerald ring I read about in one of your previous posts? Had trouble locating it in the seach mechanism.

 

[breezing]

per gemologyonline.com (http://gemologyonline.com/emerald.html):

Fluorescence: Usually inert, but may fluorese orangy-red to red with very fine emeralds

if i had a uv source i'd see how my columbian and simulant behaved.

 

[breezing]

since i was curious i went ahead and purchased an inexpensive SW and LW UV light. little fella is the columbian, larger is simulant



no reaction by either stone to SW UV (at least that i could see but room let in a little light).

LW UV - columbian (right) reacts strongly, simulant (left) no reaction. i thought the simulant would light up and was suprised that it didn't react, the only thing i know about it is it was given to my mom 35-40 years old and maybe was made before they started adding chromium (?), i have no idea. i'm kind of seeing an opaqueness to it which would also be consistent with a simulant


here's the emerald on it's own taken with flash so you can see all the "goodies" in it. i wouldn't rely on UV alone for ID'ing but since both of mine have been seen and tested by two gemologists i thought it was an interesting experiment.

 

[jleb]

Chromium emeralds will fluoresce, however the degree of fluorescence is dependent upon the amount of iron (giving the blue part of the color) which, like Thai ruby (and some African rubies) will quench the fluorescence. More Iron = less fluorescence. Other emeralds, Brazilian and African may have vanadium supplying the green chromophore (like tsavorite) and those will not fluoresce. Synthetics will also fluoresce. Chelsa filters really aren't any good for determining this, the best tool is a OPL handheld spectroscope to show you the red chromium lines at the end of the spectra. You can practice on a synthetic ruby to get the detection down for Chromium lines.

Unfortunately (or not) Chromium atoms strain the beryl crystal lattice leading to all the inclusions/cracks you see in Chrome colored emeralds. That's why the Zambian ones will have usually have a higher clarity than those from Columbia

 

[serenitydiamonds]

Colombian emeralds should not react to UV light, the impurities are mostly Chromium, some contain traces of Vanadium, and should not contain Iron. Beryl that contains only Iron impurities without Chromium is typically called Green Beryl. The 'fluorescence' that Ron is mentioning in his book is a reaction to visible light, UV is not part of the visible spectrum. Most emeralds that react to UV light are synthetic. Jieb is correct in that the most accurate method for determining the constitution of a particular emerald is using a spectroscope.

This is a great little summery of the UV reactions of some gemstones:
http://www.ganoksin.com/borisat/nenam/fluoresc.htm

In a Chelsea filter an high quality emerald will glow bright red, as will a wide selection of synthetics.

In the Emerald World, I typically use UV light to aid in determining the specific treatment that was used on the emerald. Outside of that it has little use.

--Joshua