In black 12-rayed star sapphires from Thailand, a less intense white six-rayed star is perpendicularly superimposed over a yellow/ golden six-rayed star that originates from long, thin rutile needles aligned along the first-order hexagonal prism (1010) (Hughes, 1997, p.
Due to the high concentration of hematite-ilmenite inclusions in black star sapphires, some of these gems show basal parting on their flat base, characterized by a step-like appearance.
Such inclusions have been ascribed to diffusion treatment in synthetic star sapphires (e.g.
Although some previously documented diffusion-induced star sapphires were synthetic in origin ('AIGS finds more stars', 1994; Kammerling and Fritsch, 1995; Singbamroong et al., 2015), gemmologists should remember that natural as well as synthetic starting materials may be used for this type of treatment.
Many cultures have called star sapphires "stones of destiny," with the three bands of the star believed to represent faith, hope, and destiny.
The Black Star Sapphire of Queensland Until December 2, 2007
The client believed it was a star sapphire
. Initial visual observation showed that the bottom of the cabochon was flat, whereas most star sapphires
have a convex bottom (to retain weight, in light of their high value), so this was our first indication that something was amiss.