Cubic Zirconia Zirconium, Cz Gemstone, Birthstone Meaning

Cubic zirconium (Zircon), zirconia gemstone (or Cz) is the cubic crystalline form of zirconium dioxide . The synthesized material is hard, optically flawless and usually clear, but may be made in a variety of different colors.





Benefits of Zirconia Gemstone In Jewelry

• Low cost

• Durable

• Looks like a diamond

Synthetic cubic zirconia has remained the most gemologically and economically important competitor for diamonds since 1976. It is sometimes marketed under the brand name "Diamonique".

Cubic zirconia gemstone is crystallographically isometric and, as diamond is also isometric. The physical and optical properties of synthesized Cubic zirconia gemstone, 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.



History of Cubic zirconia Cubic zirconia was discover in 1892, the yellowish monoclinic mineral baddeleyite is a natural form of zirconium oxide. It has little economic importance because of its rarity.

The extremely high melting point of zirconia (2750°C) makes the controlled growth of single crystals difficult, as no existing crucible could hold the material in its molten state.

As with the majority of grown diamond substitutes, the idea of producing single-crystal cubic zirconia arose in the minds of scientists seeking a new and versatile material for use in lasers and other optical applications.



Innovations of Cubic zirconia gemstone

In recent years manufacturers have sought ways of distinguishing their product by supposedly enhancing cubic zirconia. Coating finished CZs in a film of diamond-like carbon (DLC) or Amorphous Diamond is one such innovation, a process using chemical vapor deposition. The resulting material is purportedly harder, more lustrous and more like diamond overall. The coating is thought to quench the excess fire of CZ, while improving its refractive index, thus making it appear more like diamond. Additionally, because of the high percentage of diamond bonds in the amorphous diamond coating, the finished simulant will show a positive diamond signature under Raman spectroscopy.

Another technique first applied to quartz and topaz has also been adapted to cubic zirconia: Vacuum-sputtering an extremely thin layer of metal oxide (typically gold) on to the finished stones creates an iridescent effect. This material is marketed as "mystic" by many dealers. Unlike DLC, the surreal effect is not permanent, as abrasion easily removes the oxide layer.

Cubic zirconia gemstone versus diamond

There are a few key features of cubic zirconia which distinguish it from diamond, some observable only under a microscope,

Zirconia Dispersion:

With a dispersive power greater than diamond (0.060 vs. 0.044) the more prismatic fire of cubic zirconia can be seen by even an untrained eye.

Zirconia Hardness:

Cubic zirconia gemstone has a rating of approximately 8 on Mohs hardness scale vs. a rating of 10 for diamonds.

Zirconia Specific gravity:

A cubic zirconia gemstone will weigh about 1.7 times more than a diamond of the same size.

Zirconia 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

Refractive index:

Cubic zirconia gemstone has a refractive index of 2.176, compared to a diamond's 2.417.

Zirconia 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.

Zirconia Color:

Only the rarest of diamonds are truly colorless, most having a tinge of yellow or brown to some extent. By comparison, cubic zirconia gemstone can be made in most cases entirely colorless: equivalent to a perfect "D" on diamond's color grading scale.

Zirconia 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.