WHAT TO LOOK FOR COLOR The finest amethyst color is a strong reddish purple or purple, with no brownish or bronze-colored tints, or any noticeable color zoning when you look at the stone from the top. If the stone becomes too dark in tone, it might look black under dim lighting.
CLARITY Much of the faceted amethyst in the market is “eye clean,” meaning it lacks eye-visible inclusions. Gem professionals overlook minor inclusions when the gem is richly colored and otherwise high quality. Often this material is used for cabochons or carvings. Visible inclusions in pale pastel-colored gems reduce their value greatly.
CUT Amethyst is available in a wide variety of fancy shapes, including custom cuts. Most cutting styles are calibrated in standard millimeter sizes for use in mass-market jewelry.
CARAT WEIGHT Amethyst in large sizes is not priced significantly more per carat than smaller sizes, making it a good choice for bold jewelry designs. Unlike some colored gems, small sizes can be strongly colored, making it easier to match sets of differently sized gems.