In order to determine the karat weight of a specific item, simply look for the quality mark. Jewelry items will bear the stamp of their karatage based upon the United States or European system of marking. The United States system designates pieces by their karats—24K, 18K, 14K, 10K, etc. The European system designates pieces by their percentage of gold content. For instance, 10K gold is marked “417,” denoting 41.7% gold; 14K is marked “585,” denoting 58.5% gold; and 18K is marked “750,” denoting 75% gold; etc.

Yellow Gold
By far the most common color of gold used in jewelry, yellow gold is gold in its natural shade. Yellow gold is usually alloyed with copper and silver to increase the strength of the metal. How yellow the metal is depends upon the content of gold. A 14-karat piece of jewelry will have a brighter yellow hue than a 10-karat piece. Likewise, an 18-karat piece of jewelry will have a deeper yellow than 14-karat gold, and so on.

Spessartite:
Spessartite garnet can be red or blackish brown, but is most commonly available in rich golds, fiery oranges and warmer browns. Originally named after its occurrence in the German Spessart Mountains, there was a surprising discovery of the bright orange-red stone in Nigeria and Namibia. Until then, spessartites had existed as mere collector's items or rarities and were hardly ever used for jewelry because they were so rare. But the new location discovery changed the world of jewelry gemstones and spessartites made their way into jewelry fashion.

The most popular type of spessartite is the mandarin garnet, a gem that features a bright orange hue that ranges from that of ripe peaches to the deepest of red-orange sunsets. Signifying energy and joy of life, this stone represents the spirit of individuality and the vibrancy of life. The mandarin garnet has a remarkably high refraction of light, creating an exceptional brilliance that vividly sparkles even in unfavorable light. To bring out the best of the gem's unique color and brilliance, most are faceted cut to allow for this tremendous sparkle of fire.

The fascinating orange color featured in mandarin garnets plays an important role in Asian arts. Yellow and red, the two colors constituting orange, are not considered opposites in Asia, but rather complements to each other. The color symbolizes the continual change of life throughout the ages. Asian gods and Buddhist monks are often dressed in orange robes and the sky in Asian art is often painted orange.

Mandarin garnets were first found along the Kunene River in Namibia in 1991, embedded in the mica slate where they had been formed millions of years ago. Gemologists discovered the orange-colored stones were in fact variations of the rare spessartite gems and members of the garnet family. At that time, spessartites were fairly rare stones, even for collectors, and had hardly been used for jewelry. Some gemologists called the brilliant orange gemstones "kunene spessartine" according to their occurrence. But quite soon the term "mandarin garnet" spread throughout the international market and the stone made its successful appearance around the world. Popularity increased dramatically and the mine on the Kunene River was soon exploited. Fortunately, in April of 1994, mandarin garnets were discovered in Nigeria. The stones are now available once again in reliable amounts, though top-quality stones are rare and it is difficult to predict how long quantity will remain reliable.

Earring Back Types

Butterfly Back: A double looped piece resembling a butterfly that fits over a post. Variations on this design are called push back clasps. The basic post and butterfly back are usually used for stud earrings and lighter weight drop earrings.

Hinged Snap Backs: This clasp features a hinged post that snaps into a groove on the back of the earring. It is commonly found on hoops. Sometimes the hinged post is curved to provide more room to fit around the ear, sometimes called a saddleback.

Hook Backs: This earring backing is simply a long, bent post that fits through the piercing. Hooks have several variations, most notably the shepherd's hook and the French hook. While thin wire hooks reduce the weight of long earrings, making them more comfortable, they aren't as secure as other clasp styles.

Lever Back: A hinged lever snaps shut against the curved post to form a closed loop around the ear lobe. This clasp is very secure and good for large or medium sized styles that drop just below the ear.

Omega: Also called French clips, this clasp has a straight post and a looped lever. The hinged lever closes around the post and is held against the ear with pressure. The omega clasp is the most secure clasp, especially for the larger, heavier earrings.

Screw back: This backing is a slight variation of the standard post and butterfly nut back. Instead of pushing on the back, the nut twists onto the threaded post. A screw back post design is often preferred for expensive diamond stud earrings that require increased security.