Popis: |
In recent years, scientists have special interests in bio-vaterite found in freshwater cultured lacklustre pearls in south China. Vaterite is unstable phase and rare in nature. In this paper, we compared the thermal stability and dissolubility of aragonite and vaterite pearls. Vaterite powder of pearls can keep in distilled water for more than 20 days, and started phase transition in air above 520 °C. It is suggested that this vaterite has higher stability than natural vaterite to resist high temperature and kinds of solutions, which is a reasonable explanation why this bio-vaterite could have greater longevity than inorganic origin vaterite, and coexist with stable aragonite. |