Cubic Zirconia

Key Differentiators

• Very high SG (5.6–6.0) — heaviest common gem material; dramatically heavier than any natural simulant
• Very high dispersion — more 'fire' than diamond
• Singly refractive (SR) — no doubling under loupe
• Produced in all colors; coated varieties simulate padparadscha, alexandrite, and 'mystic' effects
• Coating check: scratched or worn girdle/culet under 10× loupe reveals true colorless CZ beneath

Natural vs. Synthetic

Synthetic cubic zirconia is commercially available (Skull melting (cold-crucible RF induction — Zefyros/Ceres process)). Distinguishing natural from synthetic typically requires microscopic examination of internal features.

• General Note: CZ is itself a synthetic material (ZrO2 with stabilizers, grown by skull melting). No natural gemstone equivalent in the trade. Synthetic: Distinguish CZ from diamond: thermal tester (CZ = simulant), RI off-scale high (~2.15), SG very heavy (~5.6–6.0), no ADR on polariscope. Distinguish from moissanite: moissanite is DR (facet doubling); CZ is SR.

Common Simulants

• Diamond: Diamond: SG 3.52 (vs CZ 5.6–6.0); thermal probe reads hot; RI 2.42 (vs CZ ~2.15); no fire comparison needed once SG tested.

Commonly Confused With

Commonly confused with: Diamond, White Sapphire, Topaz, Zircon.

Treatments

• Surface Coating (to simulate fancy diamond colors)

Price Context

Price context is approximate. GemID is not an appraisal tool. Results are indicators, not certified valuations.

About Cubic Zirconia

Cubic zirconia (ZrO2) is entirely synthetic — no natural gem-quality cubic ZrO2 exists. Produced by the skull-melt process. Key differences from diamond: SG 5.6–6.0 (much heavier than diamond at 3.52), RI 2.15–2.18 (off refractometer scale), higher dispersion than diamond. Coated CZ (TiN or other thin-film) simulates padparadscha, mystic topaz, or color-change effects; coating scratches easily — check girdle and culet under loupe. SG is the fastest single field separation test.