Figure 4

Chemical composition of HP12 by percent of total mass. Determination of constituents was conducted using X-ray fluorescence, carbon fractionation, inductively-coupled plasma optical emission spectrometry, and ion chromatography. The metals category includes Al, Cu, Fe, Mg, Ni, V, and Zn. The unknown portion is likely comprised of moisture, along with oxygen and hydrogen associated with organic and inorganic fractions [14].