How to Evaluate a Tsavorite Garnet

Tsavorite garnets are not like most deep, red garnets. Instead, they are a beautiful green color. Tsavorites were discovered about 40 years ago in Africa. They are a popular substitute for emeralds--which are fairly delicate stones--because they are extremely hardy. Here's how to evaluate a tsavorite garnet.

Difficulty: Moderate

Instructions

Things You'll Need:

• Good light
• Jeweler's lens

1. 
    
   Tsavorite-studded ring

   Rate the color. Tsavorite garnets come in many shades of green. They can be a light, "spring" green all the way to a deep, dark forest green. The most popular color is emerald green, which is a clear, brilliant and unadulterated green color.

2. Ask about the origin. Tsavorites come from an area in Africa near the Tsavo river and the Tsavo National Park. They are found occasionally in other areas along the African rock belt where many gemstone mines are located. They may also come from Tanzania. However, if your tsavorite does not come from east Africa at all, then it may not actually be a green garnet but rather a grown stone.

3. Know the names. Tsavorites are also called Tsavolites, green garnets and occasionally simply green grossularites, which means green garnet. Any of these types of nomenclature are acceptable and indicate that the gem is likely a tsavorite garnet.

4. 
    
   Tsavorites are very good supplemental stones for settings

   Weigh the stone. Tsavorites are rarely found in sizes over 2 carats. In fact, a 5-carat tsavorite is nearly unheard of. The closer that your tsavorite garnet is to 2 carats or more, the more valuable it will be. While tsavorites are relatively inexpensive stones, when you have a big one, it can be worth exponentially more than a stone that appears at first glance to be only 1/2 a carat or so smaller.

5. Evaluate the brilliance. Tsavorites have an extremely high refractive index, which means that they sparkle a lot even when there is not much light in a room. Look at your tsavorite garnet not only under a bright light or a spot light, but also in natural light and even in a dimly lit area. This will help you determine whether your tsavorite has the typical brilliance of its stone. You can also inspect the stone for inclusions, which can actually contribute to its brilliance in greener stones but can make lighter stones appear milky.

Tips & Warnings

• Always work with a trusted certified jeweler when you are making a major jewelry purchase to make sure that you get what you pay for.