Before buying Zultanite, ask four things: Does the stone show a real, reversible colour change under daylight and warm light? Is it natural, untreated colour-change diaspore? Does it come with a report from a recognized laboratory? And is the cut clean and well-oriented? Treat unsupported slogans such as “rarer than diamond” with caution — Zultanite’s documented scarcity speaks for itself.

Four questions before you buy

1. See the colour change yourself. Ask to view the stone under both daylight and warm artificial light. A genuine stone shifts between green and pink/lilac tones; strength varies by stone.

2. Confirm it is natural colour-change diaspore. The species should be named, natural origin stated, and any treatment disclosed. Colour-change imitations exist, which is why species identification matters.

3. Ask for a recognized lab report. A report from a named gemological laboratory beats an unnamed in-house “certificate.” A report documents what a stone is — and it is the buyer’s strongest protection of the stone’s value.

4. Judge the cut. Because of difficult, high-loss cutting, a clean, well-oriented cut that maximises colour change is part of the value.

Keep rarity claims in perspective

“10,000 times rarer than diamond” is marketing, not data. Zultanite’s real scarcity — single source, low yield, hard cutting — is what supports its lasting value.

A note on wear

At 6.5–7 on the Mohs scale with perfect cleavage, Zultanite is best in pendants, earrings, and protected ring settings rather than everyday knock-about rings.