"Basically, the value of shells varies based on how common or rare they are," says Chang. A single species of mollusk can live in different areas of the ocean, where their shells may bear different patterns.
「貝殼的價值，基本上就是物以稀為貴，」張議顯解釋，同一種貝類產地不只一處，不同的海域也會造成貝殼圖紋些許的差異。