Sterling Silver And Cubic Zirconia Rings

sterling silver
Silver of a fineness of 92.5%.
Silver of 921/2 percent purity
a silver alloy with no more than 7.5% copper
Sterling silver is an alloy of silver containing 92.5% by weight of silver and 7.5% by weight of other metals, usually copper. The sterling silver standard has a minimum millesimal fineness of 925.

cubic zirconia
A colorless form of zirconia that is very similar to diamond in refractivity and appearance
Cubic Zirconia is a man made gem which mimics diamond, yet does not have the same intrinsic properties such as hardness. Through a process developed in 1977, "CZ's" as they are often called, are mass produced and much less expensive than diamonds.
A synthesized mineral used as an affordable substitute for diamonds. While similar in appearance, diamonds are somewhat harder and lighter. Cubic zirconia gemstones have been made commercially since 1976.
Cubic zirconia (or CZ) is the cubic crystalline form of zirconium dioxide (ZrO2). The synthesized material is hard, optically flawless and usually colorless, but may be made in a variety of different colors. It should not be confused with zircon, which is a zirconium silicate (ZrSiO4).

rings
Each of a series of resonant or vibrating sounds signaling an incoming telephone call
(ring) sound loudly and sonorously; "the bells rang"
An act of causing a bell to sound, or the resonant sound caused by this
gymnastic apparatus consisting of a pair of heavy metal circles (usually covered with leather) suspended by ropes; used for gymnastic exercises; "the rings require a strong upper body"
(ring) a characteristic sound; "it has the ring of sincerity"
A telephone call