New Photo Posted

This post gets into the Science of the gemstone and jewelry trade. Heat treatment is very common in colored gemstones to improve and stabilize color or inclusions. House of Silva has more genuine colored gemstones in house than many stores combined and this shows you another side to all of the things we must consider as we bring these selections to you. Heating Rubies:
“Today in Chanthaburi (Thailand) we did an interesting experiment about heat treatment of the rubies we collected during our recent field expedition to Greenland (This will be the subject of a future short documentary). 
During the 1980’s ingenious people from Chanthaburi in Thailand developped a treatment technique using borax. Borax is an evaporite type mineral traditionally mined from dry lakes in Kashmir or Tibet that travelled on the Silk Roads and that is used traditionally in jewelry making to protect metals and stones from oxydation due to fire from jeweller torches. Borax was known to be corrosive for oxydes likes rubies or sapphire but a jeweller from Chanthaburi found out that using borax it was possible to repair broken stones such as black star sapphires that were regularly breaking during setting. From repairing broken stones the technique evolved into healing fractures in rough gems making them durable enough to be cut and polished without breaking. Another very positive aspect is that heating rubies with borax enables to heat rubies over 1300 degrees in air and remove also some of their milkiness (from silk or minute particles) without the stones to turn purple. 
Thanks to that heat treatment technique several ruby deposits like Mong Hsu in Myanmar, the John Saul Ruby mine in Kenya and several others like the Aappaluttoq ruby deposit in Greenland became important sources of (facet / cabochon / carving grade) rubies for the trade from the beginning of the 1990’s to nowadays.”
.
Photos: V. Pardieu / greenland ruby 
@ Chanthaburi, Thailand

This post gets into the Science of the gemstone and jewelry trade. Heat treatment is very common in colored gemstones to improve and stabilize color or inclusions. House of Silva has more genuine colored gemstones in house than many stores combined and this shows you another side to all of the things we must consider as we bring these selections to you. Heating Rubies: “Today in Chanthaburi (Thailand) we did an interesting experiment about heat treatment of the rubies we collected during our recent field expedition to Greenland (This will be the subject of a future short documentary). During the 1980’s ingenious people from Chanthaburi in Thailand developped a treatment technique using borax. Borax is an evaporite type mineral traditionally mined from dry lakes in Kashmir or Tibet that travelled on the Silk Roads and that is used traditionally in jewelry making to protect metals and stones from oxydation due to fire from jeweller torches. Borax was known to be corrosive for oxydes likes rubies or sapphire but a jeweller from Chanthaburi found out that using borax it was possible to repair broken stones such as black star sapphires that were regularly breaking during setting. From repairing broken stones the technique evolved into healing fractures in rough gems making them durable enough to be cut and polished without breaking. Another very positive aspect is that heating rubies with borax enables to heat rubies over 1300 degrees in air and remove also some of their milkiness (from silk or minute particles) without the stones to turn purple. Thanks to that heat treatment technique several ruby deposits like Mong Hsu in Myanmar, the John Saul Ruby mine in Kenya and several others like the Aappaluttoq ruby deposit in Greenland became important sources of (facet / cabochon / carving grade) rubies for the trade from the beginning of the 1990’s to nowadays.” . Photos: V. Pardieu / greenland ruby @ Chanthaburi, Thailand

  20 people like this!

View on Facebook
LOADING...