Alcohol/acetone: Sapphires, Ruby
Colorless oils, waxes, plastics to obtain better a better surface finish by hiding or filling up cracks or surface irregularities.
Colorless oils, waxes, plastics to obtain a better surface finish by hiding or filling up cracks or surface irregularitions.
Gem materials are immersed in dyes and a layer of dye deposit on evaporation.
Foils and Colourbacking
Colored foil or paper are placed behind poorly coloured stone, in a closed setting to improve colour or simulate star effect.
- Greenish Beryl ----> 450 centigrade --->aquamarine (blue)
- Brownish Beryl ---> 450 centigrade ---> morganite (pink)
- Ruby violet, brownish, dark red ----> Ruby
- Sapphire gray, dark blue. geuda, ottu ----> Blue Sapphire
- Yellow Sapphire ----> Pinkish orange (Padparaga)
- Poor quality amethyst --> 350 - 450 centigrade ----> Citrin
- Yellow Topaz ---> 550 centigrade ----> Pink Topaz
- Dark green ----> Emerald green
- Reddish brown zircon --> 1000 centigrade ----> Blue zircon
- Reddish brown zircon --> oxidizing ----> Colorless or red zircon
- Reddish brown oxidizing ----> Colorless or red zircon
Corundum - Surface diffusion
Transforming pale or colourless corundum into ruby or blue sapphire. Faceted stones are packed with transition element additives and heated to over 1750 centigrade which produces a very thin coloured layer on the surface.