Details not required for Students of EPS2 (concepts are required)

Heat only	1300 C	possible asterism
	1600 C	removes silk and asterism
Heat and reducing atmosphere	1600 C	develops blue color
Heat and oxidizing atmosphere	1600 C	diminishes blue color
Extended heating	1800 C	diminishes banding and strain
Diffusion and heat	1800 C(+TiO2)	asterism
	1800 C (+TiO2,Fe oxides)	blue color
Heat near melting point	+Cr2O3	red and other colors

Gem dealers who do a lot of business in Thailand have not been able to learn the methods. Onegem dealer offered what he knows for sure: that the method is fairly primitive, that the details of treatment vary from miner to miner, and that the material is treated as rough rather than after cutting.