To confirm this, I had a friend test a malachite sample a few years ago, using the method of x-ray diffaction. The results found were copper, carbon and oxygen, which are the constituents of malachite. No arsenic or other metals were found.

My feeling about the malachite sickness–please correct me if anyone out there knows differently–is that copper dust entering the lungs is very soluble and quickly enters the bloodstream, causing headaches, vomiting, and other symptoms. As compared to silica dust, which is much less soluble and builds up in the lungs, the copper possibly sickens one quickly enough to cause the cutter to stop cutting.

A good way to avoid these problems is by wearing a proper mask or respirator, and having a good water source to reduce dust emissions.