an imitation diamond made from rock crystal or glass or paste
"She pinned a sparkling rhinestone to her lapel, which caught the light just like a real diamond despite being made of clear glass."
An artificial diamond, strass.
"She fastened a rhinestone to her dress collar just before the ball began."
Made of or encrusted with rhinestones.
"The bride's gown was made of or encrusted with rhinestones that caught every flash from the camera lights."