Jeffrey Bergman has been collecting trapiche sapphires for over a decade and has assembled the largest collection known, rivaling the quality of pieces in the finest museum collections.
While the vast majority of trapiche sapphires are either opaque blackish blue with gray spokes or translucent dark gray on light gray, very occasionally, he would acquire a translucent gemmy vivid blue on snow white trapiche sapphire.
The collection on display at the Gem & Jewelry Exchange (GJX) in Tucson this year was made up of is comprised of several dozen of the typical opaque or gray type trapiche sapphires...but then there were three of gem quality; a 3.90ct and an 8.70 carat gem with GIA reports, and an extraordinary 36.16 carat gem with GRS and Gubelin lab reports.
His collection was on display at GJX in booth 106 with Mauro Panto of "The Beauty In The Rocks". With price points ranging from a few hundred dollars per piece to many thousands per carat I am sure that he was quite successful.
GRS gave a special comment “unusual translucent vivid blue color zoning” and Gubelin wrote one of their coveted full page appendixes where they call it an “extremely rare” and remarkable gemstone”.
The Gubelin lab report and appendix:
“The Spanish word trapiche, cogwheel in English, designates the agricultural tool which in former days was used to crush sugarcane. In the world of gems the same term is used for gemstones which show a characteristic six-rayed star pattern in cross-section.
For a long time this peculiar appearance was only known from emerald, and is due to bands of dark inclusions which radiate from the center of the crystal – the optic axis – to the crystal faces. Only in the past twenty years other trapiche gemstones have been discovered, namely trapiche ruby, trapiche tourmaline, and trapiche sapphire.
Find the article at:
http://www.agta.org/pressroom/newsletters/prismnl2013volume3/index.html#/24/
The Gubelin lab report and appendix:
“The Spanish word trapiche, cogwheel in English, designates the agricultural tool which in former days was used to crush sugarcane. In the world of gems the same term is used for gemstones which show a characteristic six-rayed star pattern in cross-section.
For a long time this peculiar appearance was only known from emerald, and is due to bands of dark inclusions which radiate from the center of the crystal – the optic axis – to the crystal faces. Only in the past twenty years other trapiche gemstones have been discovered, namely trapiche ruby, trapiche tourmaline, and trapiche sapphire.
While the trapiche affect of tourmaline and ruby is caused by similar inclusions as in the trapiche emeralds, the trapiche effect in sapphires is due to a strong color banding parallel to the hexagonal growth zoning. The blue color is mostly concentrated along the angles of the crystal forming a blue star, while white zones are found between the star segments. Such trapiche sapphires are only known from Burma and are extremely rare.
This 36.16 natural sapphire described in the above mentioned Gubelin Gem Lab Report displays a distinct and well centered star. In addition, this remarkable gemstone has been spared thermal treatment. Such a combination of characteristics is very rare in Burmese sapphires of this size.”
This stunning example was featured in the Las Vegas Show report by Gary Roskin in the Summer/Fall edition of the 2013 Prism magazine (a production of AGTA). The extra fine trapiche sapphire is 12.29 carats, set in white gold and flanked with asteraited diamonds.
Find the article at:
http://www.agta.org/pressroom/newsletters/prismnl2013volume3/index.html#/24/
You can find Jeffery Bergman at:
jeffery@primagem.com
http://www.primagem.com/
No comments:
Post a Comment