What you are describing should be a pendant made of crystal mud. In the production process, the crystal mud is made into balls and colored glass beads are added. This craft existed in ancient China, but in modern times, it is relatively easy to make glass bottles and beads, so this kind of pendant is not uncommon. However, crystal mud may release gases harmful to human body during soaking in water, so it is not recommended to contact or inhale for a long time. In addition, in order to ensure the safety of pendants, it is recommended to buy products from reliable manufacturers.