Read the directions supplied with your specific adhesive and test the complete material combination on a hidden area or spare sample.
Check what failed
Look at both surfaces. Adhesive remaining only on the stone suggests a different problem from adhesive remaining only on the object. A clean separation, torn coating or flexible substrate each points to a different compatibility question.
Review preparation
Dust, oil, polish and incompatible cleaners can interfere with contact. The stone backing may also carry manufacturing residue. Repeat the project only after testing the exact surface and embellishment combination.
Review placement and movement
Too little contact, excessive squeeze-out, large gaps or moving the item during cure can all contribute. Flexing and rubbing after cure may also lift rigid decorations from a soft base.
Change one variable at a time
Use scrap material to test preparation, adhesive quantity, spacing and cure separately. If everything changes together, you will not know which decision improved the result. Record the sample that works before returning to the final item.
Quick checklist
- Inspect both failed surfaces
- Retest preparation
- Consider flex and rubbing
- Change one variable per test