ASBESTOS, ASBESTINE, AND MINERAL NOMENCLATURE: ANALYSIS OF A MYSTERY ASSEMBLAGE AND THE CHALLENGES OF REGULATING NATURAL MATERIALS

The product called Asbestine is a mystery to many asbestos analysts and public health officials. An Internet search only creates more confusion, since the resulting hits will include references to various mineral species, as well as a definition for “asbestine” as an adjective indicating that a substance has asbestos-like qualities. In fact, Asbestine was a trade name for materials mined from the talc belt in St. Lawrence County, New York, and sold as a filler for varnish, paint, paper, rubber, and other products. To help investigators recognize Asbestine if it is encountered, mineralogical analysis techniques were applied to a sample of Asbestine in the possession of the Occupational Safety and Health Administration Salt Lake Technical Center. This sample was studied using stereo and polarized light microscopy, powder x-ray diffraction, and other methods. It was determined that Asbestine is a mixture of minerals, and contains at least one mineraloid assemblage consisting of different phases in relatively short-range domains. The main species present are prismatic tremolite, prismatic anthophyllite, talc, and quartz. However, the powdered form of the product introduces challenges when attempting electron beam analyses such as TEM, EPMA, EDS, and LA-ICP-MS. Furthermore, the mineraloids appear to be transitional metamorphic forms that have not reached a stable thermodynamic state, and appear to consist of amphibole, talc, and pyroxene. This presentation will exhibit some of the physical, crystallographic, and bulk chemical properties of this material. The results of this investigation also illustrate the challenges of using common analytical techniques on mixed phases and mineraloids, as well as exemplify the discontinuities and limitations surrounding the practice of regulating commercial mineral products based on their mineral names.