Saturday, January 05, 2008

The Finished Gem; Colombian Emerald Part III


By Richard W. Wise, G.G.

©2007

We spent most of the afternoon watching and asking questions about various aspects of the cutting process. It was a unique opportunity to sit at the feet of a master, to watch, listen and learn. (image: left: Murmurs of a goddess; Blue Morpho Butterfly of Colombia)

Step #2: Dopping

Before the faceting operation can begin, the pre-formed stone is first affixed to a stick to allow the lapidary to handle it. This age old method involves embedding the preform in a dab of shellac at the end of a 1” wooden dowel. The shellac is first heated until sticky over the flame of an alcohol lamp. The stone is placed at just the right angle and pressed into the shellac and allowed to cool. This process is repeated several times during faceting.

Step #3: Placing the Facets



Faceting is the most precise phase of the cutting operation. Facets must be cut uniformly in a precise pattern to bring out the brilliance of the gem. The faceter can only do what the pre-former has determined. If the ratio between the width and depth is correct the stone has the potential to be fully brilliant, if it is cut to shallow and there is insufficient depth, light will leak out the pavilion creating what is called a window in the gem.

Argotty’s Well:

Adolpho Argotty likes a window; I’ll go further he seems to actually prefer a windowed stone though his definition of a window is not quite what you might expect. He is not using the word to describe a stone through which you can read the New York Times by placing the paper beneath the table of the gem. He likes to push the envelope, to setup the proportions in such a way that the viewer can look into the table of the finished gem and see right down into the heart of the stone to the depth of the pavilion facets. The area under the table does not refract light, rather it draws the eye in and deep into the very heart of the gem. This requires a subtle touch. Viewed perpendicular to the table, an emerald fashioned in this way does not have a true window, but the center of the stone is like a deep well of green with little or no refracted light visible through it. This sort of window, he believes, allows you to see the color and appreciate the crystal of a fine emerald.

Step #4: Polishing:

Polishing is the final, actually the final series of steps in the cutting process. It is like the wedding night, the time when the virginal and reluctant bride fully reveals her charms. The final polish allows you to evaluate the four Cs of the connoisseur, (Color, Cut, Clarity and Crystal) The cutting/polishing process uses a series diamond compounds that like sandpaper are divided into various sizes or grits. Grits may be divided into two basic types; cutting grits and polishing grits. The pre-former begins with a fairly coarse, 300 grit, that allows him to shape the stone. The polisher uses several progressively smaller grits ending with 15,000 diamond grit to secure the final mirror-like surface luster.

The Legend of Fura Tena:

As with many legends there appears to be more than one version of this one. According to one version, a short one, in the beginning there were two Gods; a male named Fura and his consort the goddess Tena. (follow this link to a very different version) It seems that Tena had a roving eye and she took up with another god named Zarue and they became lovers. When Fura discovered that his lover had been unfaithful he cried and his tears dried into emeralds. Tena's murmurs of sadness became the beautiful blue butterflies of Colombia (Morpho didius Hopffer). The creator turned them both into stone and turned Zarue into a river (the Minero) that runs eternally between them.

This formation (right) shot from above is known as FuraTena. On the valley side and not visible here the monolith is divided into two cliff faces and separated by the Minero River. (photo: Richard W. Wise) A better view by Robert Weldon can be found here

Not quite a goddess but the lovely young lady pictured at left, an occasional emerald broker, has no doubt broken the odd heart and caused the shedding of more than one tear.



Next: Buying Emerald; A Journey to a rural miner's market in Boyaca...Stay Tuned










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3 comments:

Cassandra_Moderna said...

Dear Mr. Wise,

Please! Where is the photo of the finished emerald?

Tenney Naumer, Vitória da Conquista, Bahia

Richard W. Wise said...

Tenney,
Understand your frustration. Can't seem to get a good shot of the stones. Will try again this week.

Best,
Richard

P.S. Always wanted to visit Bahia.

Anonymous said...

Richard, could you please review

http://gemologyonline.com/Forum/phpBB2/viewtopic.php?t=4529&

and reply via email with insight on the topic " WilfredGuerin@Gmail.com "


Thanks in advance for your help