Stones found in bags of cacao

It is very important to clean cacao beans before the manufacturing process starts. There are four stages to cleaning. The first stage removes anything metallic/magnetic. The second stage removes any other other objects. The third stage uses a vacuum aspirator to remove light items such as leaf fragments. The fourth stage exposes the beans to very high heat (~200C) for a very short period of time (~2sec) to kill any bacteria on the shell.