A Star in a Sea of Red
A star ruby is a ruby that shows asterism — a six-rayed star that glides across the dome of the stone. It combines two prized qualities: the warm red of ruby and the moving star of a cabochon gem. Sri Lanka is one of the classic sources of fine star rubies.
How the Star Forms
As with star sapphire, the effect comes from microscopic needle-like rutile inclusions arranged in three directions. Cut as a smooth cabochon, the stone reflects light into a six-rayed star, best seen under a single light source.
What Affects Value
- Star quality — sharp, straight, well-centred rays.
- Body colour — a strong, even red is most prized (purplish or brownish tints reduce value).
- Translucency — a glowing, semi-translucent body is ideal; very dark, opaque stones less so.
- Cut — a symmetrical, well-domed cabochon centres the star.
Buying Tip
Tilt the stone under a single light — the rays should stay straight and centred, and the body should glow rather than look flat and dark. Buy from a licensed dealer; see our buyer's guide.
See the Source
Browse Ratnapura accommodation to explore the home of Ceylon star gems.