Cubic Zirconia Rings
Tru-Diamonds™ are created under exacting laboratory conditions by highly skilled craftsmen, using a scientific process that heats minerals to over 5 000 degrees. Then every flawless, ice-white Tru-Diamonds™ gem is perfectly cut and polished to the same exacting standards as mined diamonds. The simulated diamonds look as authentic as those excavated in mines and even jewelers struggle to tell them apart. See how many compliments you receive when wearing Tru-Diamonds™ – and no one will know the difference unless you tell them!
When graded in terms of the “Four C’s” (colour, clarity, cut and carat size) that professional gemologists use to grade mined diamonds, every Tru-Diamonds™ gem measures up to the finest grading. They are ice-white in colour, flawless in clarity, perfectly cut and the same carat sizes – they even cut glass! Each Tru-Diamonds™ item comes with a comprehensive triple guarantee that no other jeweller will give you. Once you see Tru-Diamonds™ jewellery for yourself you will understand why celebrities, those in the media spotlight and the very wealthy choose Tru-Diamonds™ for the status, peace of mind and huge savings on insurance.
According to Wikipedia 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). It is sometimes erroneously called "cubic zirconium".
Because of its low cost, durability, and close visual likeness to diamond, synthetic cubic zirconia has remained the most gemologically and economically important competitor for diamonds since 1976. It is marketed under brand names such as "Tru-Diamonds". Its main competition as a synthetic gemstone is the more recently cultivated material, synthetic moissanite.
Cubic zirconia is crystallographically isometric, an important attribute of a would-be diamond simulant. During synthesis zirconium oxide would naturally form monoclinic crystals, its stable form under normal atmospheric conditions. A stabilizer is required for cubic crystals to form, and remain stable at ordinary temperatures; this may be typically either yttrium or calcium oxide, the amount of stabilizer used depending on the many recipes of individual manufacturers. Therefore the physical and optical properties of synthesized CZ vary, all values being ranges.
It is a dense substance, with a specific gravity between 5.6 and 6.0 — at least 1.6 times that of diamond. Cubic zirconia is relatively hard, at about 8 on the Mohs scale— slightly harder than most semi-precious natural gems. Its refractive index is high at 2.15–2.18 (B-G interval, compared to 2.42 for diamonds) and its luster is adamantine. Its dispersion is very high at 0.058–0.066, exceeding that of diamond (0.044). Cubic zirconia has no cleavage and exhibits a conchoidal fracture. Because of its high hardness, it is generally considered brittle.
Under shortwave UV cubic zirconia typically fluoresces a yellow, greenish yellow or "beige". Under longwave UV the effect is greatly diminished, with a whitish glow sometimes being seen. Colored stones may show a strong, complex rare earth absorption spectrum.
There are a few key features of cubic zirconia which distinguish it from diamond:
Dispersion: With a dispersive power greater than diamond (0.060 vs. 0.044) the fire of cubic zirconia is more prismatic.
Hardness: Cubic zirconia has a rating of approximately 8 on Mohs hardness scale vs. a rating of 10 for diamonds.
Specific gravity: a cubic zirconia will weigh about 1.7 times more than a diamond of the same size.
Flaws: Contemporary production of cubic zirconia is virtually flawless, whereas most diamonds have some sort of defect, be it a feather, included crystal, or perhaps a remnant of an original crystal face (e.g. trigons).
Refractive index: Cubic zirconia has a refractive index of 2.176, compared to a diamond's 2.417.
Cut: Some cubic zirconia gemstones are cut with facet shapes which differ from those typically used for diamonds. This difference would be visible under close inspection with a loupe.
Color (or more precisely, the lack thereof): Only the rarest of diamonds are truly colorless, most having a tinge of yellow or brown to some extent. By comparison, cubic zirconia can be made in most cases entirely colorless: equivalent to aperfect "D" on diamond's color grading scale.
Thermal conductivity: Cubic zirconias are thermal insulators while diamonds are among the most efficient thermal conductors, exceeding copper. This makes telling the difference between diamond and cubic zirconia quite easy for those with the right instruments.