Search results
Diffusion. Diffusion was originally used on sapphires. Chemicals, like beryllium, were infused at high temperatures, and actually penetrated the gems. Early diffusion only produced color on the surface of the gem's surface and was referred to as "Surface Diffusion".
Diffusion treatment is a popular method for treating star sapphire, since the treatment will increase the asterism (the star effect in sapphire and ruby). The diffusion process may reach a depth of half a millimeter into the gemstone.
Lattice diffusion is a treatment process that uses heat and chemicals to diffuse an element into a gemstone to artificially change its color. Lattice diffusion–treated sapphires can be any color. In some cases the added color is shallow. In others, it goes all the way through the stone.
28 maj 2020 · The key indicator of diffusion is color bleeding — dark concentrations of the stone’s color — around pits and fractures that extend to the stone’s surface. Other indicators of treatment include melted crystals, spotty stripes of color, fractures around inclusions, and pits on the surface.
31 lip 2015 · The synthetic sapphire’s concentration vs. depth profile revealed that concentrations of Be, Mg, Ti, Fe, and Ga decreased significantly when the laser ablation spots went deeper into the stone. GIA examines a multi-elemental diffused and melt-grown synthetic sapphire for the first time.
17 sty 2003 · First, formation of ice lenses in freezing soil sorts stones and soil by displacing soil toward soil-rich domains and stones toward stone-rich domains. Second, stones are transported along the axis of elongate stone domains, which are squeezed and confined as freezing soil domains expand.
4 lip 2016 · The published data enable estimating (i) diffusion resistance factor of a sandstone via knowledge of its total porosity and (ii) the sorption isotherm via knowledge of the stone’s nature and specific surface area.
