Color: purple with bluish or reddish overtones.
Tone: light to dark. Very light or very dark are less desirable. Rich, deep reddish-purple is the finest quality.
Transparency: usually with no visible inclusions, but sometimes the unevenness of the color bands can be seen. Correct faceting is imperative.
Price structure: top commercial amethysts of 2 to 8 carats range from
US$10 to US$20 per carat. Very fine deep reddish-purple stones of more than 10 carats command premium prices of more than US$30 per carat.
