Our Location
Unit F1, 6/F, Kaiser Estate Phase 1, 41 Man Yue Street, Hung Hom, Kowloon, Hong Kong
Stone Guide: CZ, Nano Stone, Lab-Grown Diamond & Natural
After the metal, the stone is the biggest lever on what a piece costs and what it looks like at retail. We set four families of stone. This page explains what separates them, where each one belongs, and what the choice means for setting and after-sales.
The four stone families we set
| Stone | What it is | Hardness (Mohs) | How it looks | Cost position |
|---|---|---|---|---|
| Cubic zirconia (CZ) | Zirconium dioxide, cut and polished | 8–8.5 | High dispersion — strong fire and colour play; full colour range including champagne, emerald green, blue and red | Lowest |
| Nano stone | Nano-crystalline synthetic with a much finer grain structure than conventional CZ | Supplier data supplied per lot | Sharper facet edges and a whiter, quieter look; less fire than CZ, closer to diamond in tone | Mid |
| Lab-grown diamond | Carbon, grown by CVD or HPHT | 10 | Diamond optics: refractive index 2.42, dispersion 0.044 — white brilliance rather than coloured fire | Highest |
| Natural stone | Mined gemstone | Varies by species | Depends entirely on species and grade; each parcel is different | Quoted per parcel |
Hardness is not toughness. CZ is hard enough for daily wear but chips at the girdle if a prong is set too tight — which is why setting pressure matters more than the hardness number.
What the choice changes at the setting bench
- Under 1.5 mm, seat type decides survival. Tiny CZ is set in a bezel or in a pavé channel with the metal closed over the edge; prongs at that scale are too small to hold reliably.
- CZ is brittle at the girdle. Prongs are formed to sit on the crown edge, not pinched onto the girdle. We do not glue stones, because glue fails silently in transit.
- Nano stone takes a sharper polish and holds a facet edge longer, so it is the better choice for a large flat table where any rounding shows.
- Lab-grown diamond tolerates tighter prong pressure, which is why it is usually prong-set or bezel-set with a thinner wall than a CZ of the same size.
- Coloured CZ varies by lot. Champagne and emerald tones shift between parcels, so stones are tone-sorted before setting — a bracelet set straight from two parcels will show a two-tone band in daylight.
Where each one belongs
CZ carries volume fashion lines, seasonal colour and any design where the stone is decorative rather than the reason to buy. Nano stone sits in the middle: pieces that need a clean white look and a longer wear life than CZ, at a fraction of the diamond price. Lab-grown diamond is for bridal, anniversary and any line where the customer will ask what the stone is. Natural stone is quoted per parcel, and we will tell you honestly when a parcel is not worth setting.
How long they last
CZ dulls over years: surface abrasion and household chemicals take the polish off the table first. Nano stone resists that better because the grain is finer. A diamond is unaffected by normal wear, but the setting around it still needs checking, which is why we recommend an annual prong check on diamond pieces.
What we can send you
Stone specs are recorded per SKU. On request we can supply the supplier’s hardness and refractive index sheet for a nano stone lot, and the grading report reference for a lab-grown parcel, so your listing can state what it is selling rather than what a competitor claims.
Related references
- Jewelry size guide — ring, bangle, chain and earring measurements before you specify a stone size.
- Materials and finishes — the metal and plating side of the same decision.
- 925 silver versus gold plated — how base metal and plating interact with stone choice.
- How we quote — how stone family and stone count move the unit price.
- All resources for wholesale buyers — the full reference index.
Not sure which stone fits your price point? Tell us the target retail price and the look you want, and we will recommend the stone and the setting that get there.