This gemstone is a Laurellite. It demonstrates a reverse Alexandrite color change. It contains copper and comes from Mozambique.
The following tourmaline tale of sad and glad was written in April 2002 and though the set up is fictional, the stone discussed (posted above) and the events in the tale are real. It turned out to be a Reverse Alexandrite Color Changer, that I have come to call “Laurellite” since it is a new variety of Elbaite (lithia tourmaline). It also became one of the first gem quality tourmalines to be identified by the GIA, from Mozambique, with copper as a coloring agent (chromophore).
A tourmaline tale of sad and glad
I would like to welcome back to the fold all the gentle tourmaline from the cafeteria. Our next speaker will be Miss Rainbow, who will speak on the hunt for the bluer side of purple. I am sure that her colorful tale will be a joy for everyone present.
Thank you for the introduction and before I start the tale, I would like to say that the cutter was completely cooperative with the gathering of information on the bluer side of purple. The cutter’s delight with color started at an early age. When his parents introduced him to lapidary at the age of 13 (to keep him from blowing up the house with his chemistry set), his love of color was the foundation for his evolving love of gems. His interest in minerals had been focused on secondary copper minerals, that usually have lovely colors. At first the cutter only polished cabochons, but within a few years he had been infected with an interest in faceting. At the tender age of 15 the cutter emptied his savings account (much to the trepidation of his mother) and purchased a platform faceter from it’s inventor.
Since the cutter had very limited resources, most of the faceting material he got to cut came from adults that his father had found threw one of his old bosses. The closest personal relationship that the cutter developed in lapidary was with the old boss. Fulton was a Canadian, who had come from a rural background with very limited financial resources and who became a vice president of Esso (gigantic oil company). His Polish wife would fee the cutter and Fulton would speak of wisdom and beauty, along with giving him treasures of crystal color. He had ample resources and talent, but little time to be creative. The more tourmaline that the cutter saw, the surer he was that this would be his love in gems. One night, as a casual offering, the cutter was given his greatest prize, a Rubellite from Madagascar, The cutter has since seen bigger, cleaner, and redder tourmaline, but none are more prized. The cutter transformed the rough into a non-calibrated emerald cut, since he never worried about setting stones in his youth. Other tourmalines followed, but in a few years the cutter moved on to many other hobbies and adventures in the next thirty or so years, but no cutting.
After tragedy struck the cutter in his late forties, he looked for meaning in his life and looked at the gems he still possessed from his youth. A few years passed and the gem’s (Rubellite in story) beauty still drew him, but it was finally the needs of a friend that got him started back into faceting. He also realized that he would never find nice tourmaline for a colorful collection without cutting them. Doors were opened to Africa through the inter net and the tourmaline that flowed to Mars had such color, that the cutter was and still is overwhelmed. Still he craved more colors and shades. There developed a need to see tourmalines that mimic and perhaps improved on the color of other gems. This also includes some shades that are distinctly tourmalines. One part of the spectrum still eluded him, the bluer shades of purple.
He had read that tourmaline in those shades had come from Siberia and had been given the name Siberite. This information was not unalloyed with the assertion that the name had come to be used for purplish red tourmaline or another name for Rubellite. Old web pages were scanned and new ones discovered. Material was purchased and cut, but none measured up. Most of the material turned out to be part of a watermelon style tourmaline with bluish gray centers and a pink coat that could not be salvaged. Even if a subtle color blend could be salvaged the color did not look that nice.
Finally a stone was offered from Africa that was purported to look like a paler iolite. The miner had had it for years, but it took the master to see it’s true value. When the cutter received the stone, it was obviously a partial watermelon style crystal. The color of the center was a nebulous shade of pastel blue and the small amount of pink shell still remaining on the stone was badly fractured and could not be used. The cutter was disappointed, but it was a different tourmaline and the search must go on. The pink skin was ground off along with a great deal of the depth of the stone because of bad flaws. the stone’s remains were preformed into a piece that would cut a 14mm by 10mm oval. It sill had flaws, but nothing bad. It was quite thin for it’s girth, but the cutter pushed on. A small area of, pink like feather remained in the stone and gave the cutter hope that this would be an interesting stone. It’s color seemed to be Aquamarine-like in the incandescent glare of the work lights, but the cutter knew that this stone would not speak it’s true color until it was free of the wax and dop stick. The work progresses, but problems appeared. The stone’s limited thickness lead to shallow angles and a potential of naturals around the girdle. A lesser stone would have been cut down, but the need for a definable color kept the cutter set on the biggest thickest stone.
The tourmaline polished well, but with a propensity for fine scratches on the acid soaked tin/lead lap. The pavilion was completed and then the real fun began. The table would not clear. The cutter tried everything reasonable, but surface continued to deteriorate. Finally the cutter paused, turn out the light and growled. What to do? By the next day a plan was formulated. the cutter was to perform the kamikaze strike. He would grind down the table and lap the surface a finely as possible. He would put on the tin/lead lap and while keeping the ph low with ample acid, do a fast polishing job on the table as quickly as possible. As soon as the table was completely polished, he would stop, stop, stop. Even if some light marks, that would not be visible to the naked eye remained, he would stop, stop, stop. To go beyond would make it worse. The tension was a palatable and as adjustments were made to the head, the table was not progressing as fast as it should. Would bad marks develop or would the attack be successful? Each time the table touched the wheel the question was formulated in the mind of the cutter, but it was not yet time to stop. Keep the acid high, keep the pressure moderate, plenty of alumina and adjust with all the alacrity that you posses. Finally the last edge of the table was polished and faint marks had appeared in the last few moments of the effort. Touch again? no, no, no, the table looks great by eye and the loop is put to rest.
The cutter found out later how fortunate he had been that a table perpendicular to the c axis had not been the preferred direction. (the stone does not display a significant amount of dichorism) When he started polishing on one of the mains that definitely was perpendicular to the c axis, the amount of undercutting cause by sworf removal was impressive. It was still acceptable to the cutter’s eye on a side facet and without the loop, but it would have been very disappointing on a table. The shallow angles caused by 25 degree mains and problems with the preformer’s cam, lead to a significant amount of polishing corrections for the meeting of the facets, but finally the work was completed.
Boiled off the dop stick and cleaned the stone was ready to speak. The first view of the stone was made under the poor florescent lighting conditions in the cutter’s kitchen. The stone was a medium light, slightly bluish violet. It looks like a spinel! This is a color the cutter had never seen in tourmaline, but wait what does it look like in the incandescent work lights. It is a medium steely blue! Violet in the cool florescent lights and blue under the reddish incandescent lights. Wow! This is just the opposite of the color change/shift for sapphire and spinel and certainly not expected. The final mix was seen in the bluish light of early morning the next day. when the stone displayed a richer more saturated mixture of both blue and purple. It was the best under the florescent at work and the sun later in the day, where it was a more uniform slightly bluish lavender. One small step for the completion of the circle of color has been cut and the cutter is content.
The stones color will never draw the eye like a hot hot pink or a Caribbean blue, but it is attractive and looks very similar to a tundura spinel. The cutter would never guess it was a tourmaline without seeing the rough or following the optical test outlined by a friend from Africa.
Thank you for coming to the meeting and I hope it proved to be a colorful and enlightening experience.