The term “gemstones” refers to either precious or semi-precious stones used in jewelry-making. Most varieties are minerals, but some rocks and organic materials are also considered as such (i.e., amber or lapis lazuli). Today, the precious varieties are diamond, emerald, ruby, and sapphire, while everything else falls under the “semi-precious” category. However, the gems in these two categories have often changed over the years.
Only diamonds have a universally accepted grading system, which was developed by the GIA (Gemological Institute of America) in the 1950s, in which 10X magnification is used for grading clarity. All other type are graded with the naked eye under a 20/20 vision standard. Another standard used solely for diamonds is the concept of “the four C’s”: color, cut, carat, and clarity. Cut is the most important standard of value for a clear diamond, since dispersion, scintillation, and brilliance are of primary significance in diamond jewelry, and none of these factors are possible without the proper cut. Clarity and color are next in importance.
For colored varieties, including colored diamonds, the purity and splendor of its color is the key factor indicating quality. This factor of color is further broken down into three parts: *hue*, *saturation*, and *tone*. Hue refers to “color.” Translucent types are produced in the following spectral hues: red, orange, yellow, green, blue, violet, purple and pink. Purple and pink are actually modified spectral hues because purple falls halfway between red and blue, and pink is actually a paler shade of red. Natural stones rarely contain pure hues, so these are further referred to as primary, secondary, and occasionally tertiary hues.
Saturation is actually the purity of the color, or the extent to which the stone is free from brown or grey hues. Those with little grey or brown are usually referred to as having “vivid” or “strong” saturation.
Tone denotes the depth of color, which can range from colorless to black, and is described as “light,” “medium-light,” “medium,” “medium-dark,” and “dark.”
Colored varieties are frequently treated in order to improve their appearance. These treatments can affect the value, and in fact, most collectors tend to stay away from treated gems. But for the average person, natural pieces of good quality can be way out of reach financially. Here is a list of some of the treatments used and their results:
Natural gemstones that have been exposed to any kind of “treatment” may no longer be called “natural,” but still qualify as “genuine.”
Synthetic varieties are not “fake.” Imitations, such as cubic zirconia, look like the real thing, but do not have the chemical or physical characteristics of the real counterpart. Lab-created (synthetic) varieties are grown under controlled conditions, so they have the exact same physical and chemical properties of gems found in nature. Because no impurities are present, created types have better color and clarity. However, since natural ones are more scarce, they continue to be regarded as more valuable.
When you purchase jewelry of any type, deal with a reputable jeweler, and make sure you understand how to properly care for your jewelry. If you buy genuine styles, get a certificate from the jeweler as well. Whatever type of jewelry you have on your shopping list, Jeweler.com can help you find just what you’re looking for.