Q: I’ve heard that some soapstones contain asbestos, and should be avoided by carvers. Then I heard that the soapstone itself was toxic, because it contains talc. Is this true?
A: More or less. California soapstone, for instance, is notorious for asbestos contamination. While one can take samples to a testing lab to make sure, this would probably only be worthwhile if one was quarrying one’s own. Most stone dealers are aware of this problem, and only carry stone that is known to be asbestos-free. Some soapstone contains silica, which can cause silicosis when inhaled. This should likewise be avoided, but is not as serious a hazard as asbestos. Granite, for instance, contains a lot of silica, but it may be carved safely if proper precautions are followed.
Talc (steatite) is still used for “talcum” (body) powder. Although in the past some asbestos-containing talc was inadvertently used for this purpose; it was the asbestos, not the talc, that was the major problem. Lung scarring is, however, associated with chronic exposure to respirable talc—to be safe, wear a dust mask when appropriate, and clean up after carving. If you are looking for a safer stone to carve that is still relatively soft, try alabaster (a massive form of gypsum, or calcium sulphate), or limestone and marble (calcium carbonate), although these may also be contaminated with silica.