Question about Emeralds

[canuk-gal]

Hello:

I have a question or two about Emeralds and how their inclusions help identify their origin. The reason I ask is I am well acquainted with a person who has been importing Emeralds from Colombia for 15 years, and a question arose recently when one of the Emeralds--purchased by a good friend--was appraised as it origin being Brazil, and not Colombian. I always understood that the buyer went to the mines herself and choose the stones she purchased (she is a native Colombian and know the area well).

My questions are:
1) could the gemologist have been mistaken?
2) how are the gems identified by mine of origin?
3) could Brazilian emeralds be sold in Colombian mines (as Columbian) since the latters sources of "good quality" emeralds are diminishing?

And help with this matter--disspelling misinformation and the like--is appreciated.

cheers

Sharon

 

[Richard Sherwood]

1) could the gemologist have been mistaken?

Yes, or he/she could have been correct.

2) how are the gems identified by mine of origin?

By the inclusions, the color, mineral content, filter reactions and spectroscopy.

Country of origin is a tough enough determination, with mine of origin being even more difficult.

Sometimes (often) the results are conclusive if you have a VERY experienced gemologist who has INTENTLY studied this particular specialty, sometimes not. Some labs have quit doing conclusive emerald country of origin ID as the delineations have gotten vaguer between some neighboring areas with similar geological characteristics.

3) could Brazilian emeralds be sold in Colombian mines (as Columbian) since the latters sources of "good quality" emeralds are diminishing?

Yes, definitely. This happens all the time with different colored stones. Stones from a country with a "lesser" name will be marketed out of country with a "greater" name. It's big business. It even happens with synthetics. I just identified a synthetic which was purchased "right at the mine". It was a beautiful, large crystal growing out of the host rock. Upon closer examination, it was determined to be a synthetic which had been carefully glued into a drilled out section of the host. The owner, (a Colombian emerald dealer), was stunned. He just about ruined my desktop with his tears.

The big identifier with Colombian emeralds is their three phase inclusions (negative crystals with liquid, gas bubble & solid crystal enclosed). Brazilian emeralds have two phase inclusions, while Colombian stones have three phase.

You can often differentiate between the Muzo area mines and Chivor area mines by the shapes of these three phase inclusions. The presence of pyrite is also another strong indicator, along with a pink or red reaction under a Chelsea filter. Color is also another indicator, with Chivor emeralds often having a little more blue modifying hue to the green body color.

It's like a detective solving a murder. He gathers more and more clues until he is confident who the murderer is, and arrests him. If there aren't enough clues to come to this conclusion, the murderer doesn't get identified. Neither does the emerald.

 

[canuk-gal]

HI:

A sound and as thorough a reply I have come to expect from you Richard: thank you for the same--you are a gentleman and a scallop.

Given this information, and not having had my emeralds tested for origin, I can only "suspect" that my gems too might be from Brazil--as they were purchased 11 years ago from this same dealer, a few years before my girlfriend's purchase (gemologist insepected).
At any rate, I am only moderately dissappointed, as these app. 11 carats of emeralds were gifted to me (birth of my son ((large cross)) & subsequent anniversary ((earrings)), and are beautiful, bright green and very clear. That the honest dealer was perhaps deceived is regretable--the onus on them for proof of origin in case of legal issues, I suppose.

Again, thank you for your thoughtful and helpful answer.

cheers

Sharon

 

[Richard Sherwood]

One quick and easy test which would be a strong indicator of origin is the use of a Chelsea filter ($35).

Colombian emeralds of medium dark hue or greater will show up strong red, while medium light tones or less will show up as a nice pink. (Many synthetics show up as very bright red, so you have to determine if the stone is natural first).

Brazilian emeralds will show up as a much more desaturated brownish red (muddy red).

It's a fun little instrument which helps with a lot of other stones as well.

Speaking of filters, the Colombian dealer who brought the rough emerald crystal to me for identification related the following reason for doing so:

He was exhibiting at a gem show when "...some punk gemology student stood in front of my showcase with some kind of filter up to his eye and scanned all my emeralds (hundreds). 'This one's a fake' he said, pointing to the rough crystal, and walked off."

Heh heh heh...

 

[canuk-gal]

Hey:

Out of the mouthes of babes.....

Will look for said Chelsea filter--or maybe wait until Christmas when I go to golf school in Boca and bring my emeralds along for you to have a look. Love Sarasota and don't mind the drive.......

Sharon

 

[Richard Sherwood]

Sarasota's definitely worth the drive. Some of the most beautiful beaches in the world. After an hour and half on the beach, all your problems go away. Just like the Corona Light commercials. Great eating spots too, and plenty to do.

Red rover, red rover, bring that cross right over!

 

[yowahking]

Country of origin is such a good topic to get into. Sounds like Richard has a good grip on things. I find it interesting to buy AZ peridot cheaper in Thailand. Tahitian pearls cheaper in HK. Australian opal cheaper in the US.
I find customers who will by an inferior Columbian emerald because someone told them not to buy Brazilian or Zambian. I find customers who will pass on a fantastic Thai ruby because they were told to only buy BURMA.
I have seen antique rings with London Blue Topaz center stones sold on Ebay as original.
I have seen certificates (bad ones) calling smokey quartz smokey Topaz.
We could get into many colored topics that could help consumers work through the BS and buy as we would buy rather than how it makes more money.