How to Evaluate Amethyst Jewelry

Amethysts are actually a type of purple quartz. They are prized for their beautiful violet to deep purple shades and, like rose and white quartz, range in clarity from nearly opaque to crystal clear. Amethysts, like most gemstones, are judged on basically the same merits as diamonds, but they are evaluated slightly differently due to their unique coloring and structure.

Difficulty: Moderate

Instructions

Things You'll Need:

• Good light
• Jeweler's lens

1. 
    
   Unless the stone is certified as completely natural, you should assume that your amethyst has been treated.

   Check the color. Generally speaking, the deeper the purple color, the more valuable the amethyst will be. However, the stones range in color from a very light, translucent lilac to a deep, royal purple. You should choose the color that you like best rather than judging solely on expense.

2. Examine the top surface. Although inclusions in colored stones are generally not a very big deal, the top surface of the stone should be smooth and unmarred. If it is scratched, dented or has visible inclusions, then these anomalies will interfere with the sparkle and brilliance of your gem.

3. 
    
   Amethysts with lots of inclusions may appear milky.

   Evaluate the clarity. The appearance of a colored stone like an amethyst generally is unaffected by interior inclusions, but if the flaws are too many or too large, they can actually make the stone appear milky or opaque. This look is preferred by some people, but it does diminish the value of the stone.

4. Look at the prongs of the setting. Sometimes metals that have been plated rather than being actual sterling silver or at least 14 carat gold can appear to "tarnish" an amethyst, leaving small rusty marks on the stone. While these can be cleaned off, they may stain the stone slightly or you may end up damaging it when you clean them off. Avoid cheap settings if you are going to invest in an expensive stone.

5. 
    
   Cushion cuts and elaborate shapes like hearts make an amethyst more valuable.

   Choose a cut. Generally, amethysts are relatively easy to shape and facet, but the more elaborate the cut or shape of the stone, the more expensive--and generally valuable--the stone will be. For example, a simple, traditional round cut stone that is one carat will not be as expensive as a heart-shaped stone that is also one carat, all other things being equal.

Tips & Warnings

• Amethysts are heat-treated to create a deeper purple. If it is extremely important to you that you have an entirely natural amethyst, then you must emphasize this to your jeweler.
• Because most amethysts are heat treated, they may also have been coated with an accompanying treatment to increase their shine. Do not use abrasive cleaners on your amethyst, since often even a retail jeweler will not know for sure if the amethyst has been coated, and inappropriate cleaners can make the stone look muddy and dull permanently.