- Jewelry Identifier
- Hallmarks
- ZIRCONIUM
* zirconium hallmark
The ZIRCONIUM hallmark: meaning, purity & value
Zirconium. When heat-treated, surface oxidizes to a hard ceramic black layer ('black zirconium' rings). Hypoallergenic, lightweight, scratch-resistant.
Published May 30, 2026
Quick facts
- Metal
- zirconium
- Common regions
- international
- Density
- 6.52 g/cm³
- Melting point
- 1855 °C
Stamps that mean the same thing
This purity may be struck into jewelry as any of: ZIRCONIUM / BLACK ZIRCONIUM / Zr. The mark differs by country and era, but the metal content is identical.
What ZIRCONIUM tells you
Zirconium. When heat-treated, surface oxidizes to a hard ceramic black layer ('black zirconium' rings). Hypoallergenic, lightweight, scratch-resistant.
How to check it yourself
- Examine the stamp under a 10× loupe — genuine marks are crisp and evenly struck, not doubled or smeared.
- Confirm the mark reads ZIRCONIUM or an equivalent such as BLACK ZIRCONIUM.
- Weigh the piece and estimate its volume — the density should land near 6.52 g/cm³ for this alloy.
- Photograph it in the Jewelry Identifier app to read the metal, hallmark, and any gemstones from the image.
- For a binding result, have an assay office or gemological lab run an XRF purity test.
* Frequently asked
FAQ
- Q. Is ZIRCONIUM the same as BLACK ZIRCONIUM?
- A. Yes. ZIRCONIUM, BLACK ZIRCONIUM, Zr all denote the same material — zirconium. Different markets and eras stamp it differently, but the purity is identical.
- Q. How do I confirm a ZIRCONIUM stamp is genuine?
- A. Look at the mark under 10× magnification for crisp, even strikes, cross-check the weight-to-volume ratio against the expected density (6.52 g/cm³ for this alloy), scan it with the Jewelry Identifier app, and — when it matters — have an XRF test done by an assay office or gemological lab.
* Try it
Identify the jewelry in your hand, right now.
Just take a photo — AI reads the metal, gemstone, hallmark, era, and an estimated value range in seconds. First two scans free, no account required.
Download on the App Store* Related