Amethyst is a transparent purple-violet variety of quartz. The best amethysts have a medium dark violet color and uniform coloring. They are rarely heated to lighten dark colors or to improve transparency. An amethyst will change color to yellow or greenish yellow after heat treatment. Long time exposure to direct sunlight may make the color fade.
The figures are based on Gemval's aggregated valuation statistics for the retail market. Irrelevant, controversial or repeat data are excluded from our analysis wherever possible. The figures are updated monthly.
Occurrence is represented in % for different weight categories.
Occurrence is represented in % for different value intervals.
Occurrence is represented in % for different clarity grades.
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