A 6.08-carat star sapphire from An Phu, Vietnam, cut en cabochon to reveal the stone's asterism: a six-rayed star that emerges under direct light and travels across the dome as the stone moves. The phenomenon is produced by intersecting needles of rutile oriented along the crystal's trigonal axes — a structural condition present in the rough that no treatment can induce. Vietnamese sapphire deposits in the basaltic north yield material across a wide saturation range; this stone sits at the pale, diffuse end of pink — sometimes called cherry blossom — where the star reads with particular clarity against a soft ground. Unheated.
 
6.08 carats / 11.3 × 8.4 × 5.8 mm / Unheated