GemologyOnline.com https://gemologyonline.com/Forum/phpBB2/ |
|
Russian Demantoid - Heat treatment https://gemologyonline.com/Forum/phpBB2/viewtopic.php?f=50&t=22184 |
Page 1 of 1 |
Author: | Marlow [ Sun Jan 03, 2016 10:22 am ] |
Post subject: | Russian Demantoid - Heat treatment |
Very interesting! http://www.igc-gemmology.net/igc34-proc ... GC3444.pdf [pdfview]http://www.igc-gemmology.net/igc34-proceedings/content/pdf/IGC3444.pdf[/pdfview] |
Author: | Stephen Challener [ Sun Jan 03, 2016 3:21 pm ] |
Post subject: | Re: Russian Demantoid - Heat treatment |
That is fascinating, and somewhat contrary to what I'd heard elsewhere--I know it's said that heat treatment on demantoids is a very low temperature process. I'd even heard numbers like 100c thrown around if I remember right. That aside, it is a rare treat to see such a nicely documented article on a treatment like this. |
Author: | Marlow [ Sun Jan 03, 2016 4:08 pm ] |
Post subject: | Re: Russian Demantoid - Heat treatment |
Interesting and a question to our mayor labs - maybe Mr. Renfro or Mr. Smith can help - whether FTIR now helps to identify heat treated russian** demantoid with horsetail inclusion so many buyer and collector wanna see? ** To my knowledge skarn hosted demantoid like Madagascar or Namibia show no fibers of asbest minerals. The serpentinite hosted D. show fibers ( Val Malenco, Iran, Pakistan) but not the horsetails like the russian stones ( don't know much about Canada and Californian D.) |
Page 1 of 1 | All times are UTC - 4 hours |
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group http://www.phpbb.com/ |