Trapiche "creation"

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Hi,

Would any gemmologist be able to explain how trapiche are formed.
I would also be very interrested to know if the process is the same between trapiche sapphires with the same kind of star (transparency, luster) as the body (like trapiche beryls) and those with low luster star (like trapiche emeralds). I have never seen any of the second type outside Burma...

Thanks

 

[valeria101]

Not a gemologist, but got a few references for the related works of a few,

The first three titles are very case in point - referring to the formation of trapiche in sapphire much along the lines (i.e. relating to similar mechanisms) of the work on trapiche emeralds by Terry Ottoway, Nature (1994), Vol 369, No 6481.

Garnier V., Ohnenstetter D., Giuliani G., Schwatz D. (2002): Rubis trapiches de Mong Hsu, Myanmar. Revue de Gemologie A.F.G., 144, 5-12

Garnier V., Ohnenstetter D., Giuliani G., Blanc P., Schwatz D. (2002): Trace-element contents and cathodoluminescence of “Trapiche” rubies from Mong Hsu (Myanmar): Geological significance. Mineralogy and Petrology.

Ohnenstetter Daniel, Garnier V., Giuliani, G., Blanc, P. (2003): Trapiche texture in precious gemstones, Université Pierre et Marie Curie (presentation). LINK

Karl Schmetzer, Henry A. Hänni, Heinz-Jürgen Bernhardt, and Dietmar Schwarz, (1996); Trapiche Rubies, Gems & Gemology, Winter, Volume 32, Issue 4

Schmetzer K., Beili Z., Yan G., Bernhardt H., Hanni H. (1999): Element mapping of trapiche rubies, Journal of Gemology, Vol 26, No5, pp.289-301

I must have compiled the list of references where these come from in 2004 - and have not looked for updates recently.
For better or worse, to me this is no more than a bit of fun - especially when oddballs like the one piece of 'trapiche and more' sapphire in the picture below (left) turns out begging for a thought along the afternoon tea.

 

[colorchange]

Thanks a lot Valeria I'm impressed

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Guess I have to go to the national research library some day to read all of this !