In most cases there is no difference: AD, short for American diamond, is the Indian market name for cubic zirconia (CZ). Indian sellers say AD, while export buyers and Western listings say CZ. The differences that matter for a buyer are the grade of the stone, the quality of the cut and the way it is set.
Why two names exist
The term AD became common in the Indian domestic market as a friendly name for diamond-look stones. CZ is the material's proper name and the term used in export catalogues, test reports and marketplace listings. Both names usually describe the same synthetic zirconium dioxide stone.
Some sellers use AD loosely for any white sparkly stone, including glass or crystal. Ask the maker to confirm in writing that the stones are cubic zirconia, not glass.
Where real quality differences come from
- Grade: trade grades describe clarity and cut quality; higher grades sparkle more.
- Cut: machine-cut stones have sharper, more even facets than rough or hand-finished ones.
- Colour: white CZ should be clear, without a yellow or grey tint; coloured CZ should be even.
- Size consistency: stones in pave work should match closely, or the surface looks uneven.
- Setting: prong or bezel settings hold better and show more light than glued stones.
How to tell CZ from glass on a sample
- CZ is noticeably heavier than glass of the same size.
- CZ shows strong rainbow flashes under a single bright light; glass looks duller.
- Glass facets often look rounded at the edges; CZ facets stay sharp.
- A maker who quotes a very low price for a large stone-set piece may be using glass.
Use one name on your listings
For customers abroad, use "cubic zirconia" or "CZ", which they will search for and which describes the stone honestly. Keep the term "AD" for conversations with Indian suppliers. Read what American diamond jewellery is for the wider category.
What this means for a buyer
Write the stone material, grade, size and setting into the specification, and keep an approved sample as the reference.
Creston & Co works for buyers only, for a fixed fee agreed in writing. We confirm stone type and setting on samples and bulk goods and supervise packing. Start with a free sourcing review.