The weathered zones of ore deposits, which no longer exist, are re constructed by inference to provide estimates of relative abundances of usable nuggets of native copper, silver, and gold in ancient times. New analyses and selected data from the literature summarize metallic impurities in native copper, silver, gold, and lead and in 2CuO₃. Cu(OH)₂, CuCO₃. Cu(OH)₂, CuSiO₃.2H₂O, Cu₂O, CuO, CuSO₄. 5H₂O and CuSO₄. 3Cu(OH)₂ (averaged), CuC1₂.3Cu(OH)₂, AgC1 and PbCO₃. The influence that these occurrences and compositions exerted upon the origin and development of metallurgy in Mesoamecica and South America is discussed in relation to new analyses and selected data from the literature. -- AATA