Diamond Powder For Gemstone Polishing
What This Process Needs To Solve
A gemstone shows every mistake. A single oversized particle leaves a scratch that no amount of further polishing will remove, which is why the buying decision in this application rests on oversize content rather than on average size or price per carat. It is also why we quote the maximum particle size on the certificate.
Yellow for general stones, black for diamond
For ruby, sapphire, opal, agate and jade we recommend HDY yellow monocrystalline micron — a regular crystal that cuts evenly on a tin, copper or ceramic lap. For finishing natural diamond, and for the hardest corundum, HDG black micron is the traditional choice: it wears better on the lap and produces the cleanest facet edges.
Work down, then stop
Faceting is a ladder from pre-polish to final. Most scratching happens when a stone moves to the final grade before the previous step’s damage is fully removed, or when the powder is not properly dispersed on the lap. We supply evaluation quantities so a new stone or a new lap can be trialled before a production order.
Recommended Grades And Size Ranges
Gemstone grades are quoted by maximum particle size, and the upper cut is reported on every batch.
| Use | Recommended grade | Size range | Why this grade |
|---|---|---|---|
| Coloured stonesRuby, sapphire, opal, agate, jade | |||
| Fine polish | HDY yellow monocrystalline micron | 0 – 0.5, 0 – 1, 1 – 2 µm | Clean facet edges with no oversize scratch |
| Pre-polish and tumbling | HDY yellow monocrystalline micron | 2 – 3, 2 – 4, 4 – 8 µm | Removes saw marks before the fine step |
| Natural diamond and hard corundumFinished stones, hardest corundum | |||
| Natural diamond finishing | HDG black micron | 0 – 0.5, 0 – 1 µm | Wears better on the lap, cleanest facets |
| Hard corundum pre-polish | HDG black micron, HDY yellow micron | 2 – 3, 3 – 6 µm | Cuts hard stone without glazing the lap |
Evaluation quantities are available so a stone or a lap can be trialled before a production order.
What has to hold
- Very low oversize content
- Uniform particle size distribution
- Clean dispersion on the lap
- No metal contamination that would tint the lap
- Consistent from lot to lot
Where it ships
Diamond Grades For This Process
Factory Direct Since 1990
Zhecheng Hongxiang Superhard Material Co., Ltd. is an integrated manufacturer and exporter of synthetic diamond powders since 1990, located in the Diamond Capital of China.
- Own manufacturing base in Zhengzhou, Henan — powder, coating and grading on one site.
- In-house particle size and SEM inspection on every batch before packing.
- Export packing with neutral or custom label, plus sample quantities for process trials.
What To Include
Describe your workpiece, process and target result. We will match the diamond grade from the existing product range.