by admin | Aug 28, 2023 | Sapphire
Heat treatment is used to improve the colour and clarity of blue sapphires (Abraham,1982; Anonymous, 1917; Fryer, 1983; Koivula and Kammerling, 1991; Kyi et al., 1999;Nassau, 1982; Pemadasa and Danapala, 1994; Scarratt, 1981, 1983, 1985a, b, 1988;Themelis, 1992;...
