Asterism
星彩効果／セイサイコウカ
星彩
Asterism
Astérisme
Glossary
Thematic
Jewellery, Technic
Reflection of light rays on inclusions causing an optical phenomenon, characterized by lines forming a star (the number of branches is representative of the type of gem). It only appears on certain stones cut in cabochon, such as sapphire and ruby (6-pointed star), which are then said star ruby and star sapphire.