1. Natural flaws: Hetian jade is a natural ore, so there may be some flaws and textures. Some of these black spots may be naturally formed, not defects.
2. Colored minerals: Sometimes, Hetian jade may contain a small amount of other minerals, such as rust, which will form black spots in jade.
3. Oil leakage: Some Hetian jade white jade bracelets will be slightly protected by oil pollution during processing and polishing. If oil penetrates into tiny cracks or flaws in the stone, black spots may be formed.
4. Stains: If the bracelet is exposed to dirty environment for a long time, it may be affected by stains and form black spots.
If you are very concerned about the black spots on the bracelet, I suggest you consult a professional jeweler or Hetian Baiyu appraisal agency to determine the nature of the black spots and their influence on the bracelet.