Sterling Silver is the most popular metal for Jewelry in the United States. Often incorrectly referred to as solid silver, Sterling Silver is actually composed of 92.5% silver and 7.5% alloy, usually copper. This proportion never varies -- it is fixed by law. Because pure silver alone is too soft for wearing as jewelry, the alloy or copper gives Sterling jewelry its added stiffness and wearing qualities.

Sterling Silver jewelry can be worn by most people, though it will tarnish with wear. To clean, use a polishing cloth or sprinkle a fair amount of dry baking powder on a soft cloth and hold it in the palm of your hand. Rub carefully to avoid scratching stones or glass components. When done, shake the powder off of your silver jewelry.

CZ Gemstone Compared to Diamonds online:

To the untrained eye, Cubic Zirconia looks identical to a good quality Diamond, but Zirconia has slightly less brilliance or sparkle than a Diamond and more fire or flashes of color. The overall effect is so similar that it can even fool a trained gemologist on occasion. One great difference between Cubic Zirconia and Diamond is weight. Cubic Zirconia is about 75% heavier than a Diamond. A piece of CZ the same size as a one carat Diamond weighs about 1.75 carats. Zirconia is also more brittle than natural Diamond and softer. Cubic Zirconia is also flawless, instead of natural diamonds which usually contain impurities and inclusions. But today Cubic Zirconia can be produced in nearly all colors, also Cubic Zirconia with inclusions are made in laboratories! Gemologists agree that Cubic Zirconia is the finest Diamond alternative because it comes closer than any other gem material to matching the characteristics of a Diamond. Most people, even trained gemologists, cannot tell the difference with the naked eye.
Caring for Cubic Zirconia

Cubic Zirconia can be cleaned with any conventional jewelry cleaner or detergent. With such a high hardness and durability, you can use a brush to clean off dirt or oil also. Ultra sonic jewelry cleaners may also be used on Cubic zirconia and will not damage the stone. However, when using soaps or detergents to clean CZ, one should wipe the jewelry dry thoroughly to avoid residue from the soap leaving a film that will dull the brilliance of the stone. Cubic Zirconia should be cleaned frequently to remove oils from skin that also dull the brilliance of the gemstone.

Like a natural Diamond? In appearance, Cubic Zirconia looks almost exactly like a good quality Diamond, although there are some slight differences:
Fire & Brilliance

Cubic Zirconia or CZ for short has slightly less brilliance (sparkle) than natural diamonds, while having more fire (flashes of rainbow colors). The overall effect is so similar to diamond that trained gemologists often require special equipment to tell them apart.
Hardness

There are only very few substances on earth harder than Cubic Zirconia. With a hardness rating of 8.5 on the Mohs' scale , CZ comes close to matching diamond's perfect 10. Yes, Cubic Zirconia will scratch glass, just like a natural Diamond.
Weight

Cubic Zirconia is about 75% heavier than Diamond. As such, a CZ's size is referred to in carats only as in comparison to Diamonds. CZs are more accurately measured in millimeters, referring to the diameter. A 6.5 mm Cubic Zirconia is equal in size to a one-carat Diamond and actually weighs about 1.75 carats.
Clarity

Because Cubic Zirconia is grown in a lab in a controlled environment, if the crystal is not perfect in clarity, it is simply not used of dust or dirt. The finest CZs are perfect in clarity, but also Cubic Zirconias with small inclusions (man made) are available in today´s market. Your Cubic Zirconia gemstones will remain sparkling clear with regular cleaning. A Cubic Zirconia man-made gemstone can be worn everyday and will never get dull or change color.
Cut

The finest Cubic Zirconia is cut to exacting tolerances, according to the proportions demanded in fine Diamond cutting. Finely cut and faceted CZs will have a polished girdle and more fire. All of our CZ's are premium faceted stones. Both the hardness and clarity of CZ allow intensive precision faceting such that the hundreds of facets in trillion, quadrillion, and radiant cuts equal the brilliance of natural diamonds / brilliants.