Synthetic Cubic Zirconia

Synthetic Cubic Zirconia (or CZ / American Diamond) 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 commercial production began in 1976. Its main competitor as a synthetic gemstone is the more recently cultivated material, synthetic moissanite.


Cause of Color :
  • Green: Chromium
  • Orange / red: Cerium, etc.

Chemical Composition :

Zirconium Oxide – ZrO2

Classification / Type :

C.Z. is a man made material. The term synthetic is used to refer to this material, even though it does not have a natural counterpart, but it exists in the mineral Baddeleyite which crystallizes in monoclinic system.

Crystal System / Forms :

Cubic System

Cuts & Uses :

Facetted cuts, beads, etc.

Dispersion : 0.060
Hardness : 8 - 8.5
Lustre : Adamantine
Magnification :

Gas bubbles, zirconium oxide powder droplets in rows, dispersive fire (orange) on pavilion facets.

Optic Character :

Isotropic (S.R.)

Pleochroism : Nil
Refractive Index / Birefringence :


Simulants (with separation tests) :

Synthetic Moissanite (doubling, dispersion, inclusions), G.G.G.. (S.G., dispersion), Y.A.G. (S.G. dispersion), Diamond (S.G., dispersion, U.V. fluorescence), Strontium Titanate (dispersion, S.G.), Sphene (optic character, doubling, dispersion), Synthetic Rutile (dispersion, S.G., doubling), Demantoid (inclusions, dispersion, S.G.), Spessartite Garnet (inclusions, spectrum, S.G.), Malaya Garnet (inclusions, spectrum, S.G.), etc.

Specific Tests :

Low see through effect.

Spectrum :

Varies with dopants used.

Synthesis :

Skull Melting Method

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