Star Sapphire
A star sapphire is cut as a dome, not a facet, because the star only appears in a cabochon. The effect comes from fine rutile needles inside the stone that reflect light as a six-rayed star.
Sri Lanka produces star sapphire in grey, blue, black and a rare golden. The sharpness of the star matters more than the body colour — a crisp star in a grey stone is worth more than a smudged one in a blue.
