About Faceted Gemstones Jewelry

Faceted stones are stones which have been cut with polished flat faces, also called facets, to enhance the reflection and refraction of light within the stone.

The first faceted gemstones were made between 800 C.E. and 100O C.E., and they quickly became much sought after for the fire and sparkle that they added to jewelry. Typically, only stones that are transparent are faceted, as the purpose of faceting is to enhance the optical properties of the stone.

The value of faceted stones is determined by four factors, known as "the 4 C's": Cut, Color, Clarity, and Carat Weight. These are most important when evaluating faceted precious stones (diamonds, rubies, sapphires, and emeralds), but they also have an impact on the desirability of semi-precious faceted gemstones. The material below discusses the 4 C's as they relate to faceted semi-precious stones. Information regarding the 4 C's as they relate to diamonds is available here .

Cut refers to the placement and shape of the facets. The facets should generally be cut in such a way that they minimize the loss of light from the back of the stone, and reflect the maximum "fire" through the top of the stone when viewed from above. Each variety of gemstone has a set of ideal faceting angles determined by the refractive index of the gem material. Facets that are cut too steeply or too shallowly will allow too much light to pass out of the bottom of the stone, resulting in a stone that is very dark in the center when viewed from directly above, instead of being fiery and bright. Stones that have a dark center are generally less expensive than stones which reflect more light.

Color refers to both the hue and the color saturation of the stone. The ideal color for each variety of semiprecious stones varies both with the gem and with the preference of the buyer. Amethyst, for example, is available in shades which range from a very pale lavender to almost black. The most popular and valuable color range for this stone is a medium to deep purple, but some people prefer the look of the colors on one of the extreme ends of the spectrum. Since the overwhelming purpose of jewelry is to enhance the beauty in our lives, these people should choose stones that they find appealing without feeling limited by the so-called "ideal" color of the stone. Color saturation refers to the depth and evenness of the color within a stone. Stones with obviously uneven color, or "color zoning", are generally cheaper than stones which show uniform color and intensity.

Clarity refers to the ability of the gem to transmit the light which enters the stone. Blemishes (surface imperfections) and inclusions (internal imperfections) can cause the stone to absorb or reflect away light, reducing the fire and brilliance of the stone and resulting in dark spots. In general, the fewer and smaller the inclusions and blemishes, the more desirable the stone. Sometimes, however, the presence of inclusions makes a semi-precious stone more valuable, as in the case of plant and insect remains encased in amber, or the golden-colored needle-like inclusions of rutilated quartz. Clarity is generally less of an issue with cabochon-cut and tumbled stone jewelry, where some reduction in the transparency and sparkle of a gem is often a secondary consideration to the unique patterns and visual interest that natural inclusions can add to a stone.

Carat Weight is simply a measure of the weight of a gemstone. A carat is one-fifth of a gram, and there are 100 points to a carat. Because different types of gemstones have very different densities, the size or volume of a one-carat stone, while fairly constant within a gem variety, varies greatly from gem type to gem type. Semi-precious stone jewelry is therefore much more often sold using descriptions of size, which are immediately meaningful to the average consumer, rather than carat weight, which would require that the consumer be familiar with the varying densities of the stones in question.