Refining the identification of native American pipestone quarries in the midcontinental United States

Midcontinental pipestone quarries in Missouri, Minnesota, Wisconsin, Illinois, Ohio, and Kansas were utilized by a number of native cultures from 5000 YRBP through historic times. Except for Gunderson's pioneering work on catlinite, the mineralogy of these sources was poorly understood until recently. For fifteen years, a University of Illinois team of archaeologists and geologists has used well-established mineralogical methods (X-ray diffraction [XRD] and reflectance near-infrared spectroscopy [NIS]) to identify and characterize nine pipestone quarries and match sources with archaeological artifacts from major Hopewell and Mississippian culture sites. NIS analyses of raw materials from nine major pipestone quarries show distinct mineralogical differences between sources but relatively uniform composition within each source. The major distinguishing minerals estimated from NIS spectra match very well with earlier results from XRD and inductively-coupled plasma (ICP) analyses. Results demonstrate that NIS is a reliable non-destructive technique for discriminating between midcontinental pipestones and for sourcing pipestone artifacts.