corundum, Colombia.12, gems

Colombia has long been reputed for producing fine emeralds. More recently, corundum has been recovered from streambeds and sands on both sides of the Rio Mayo, which forms part of the border between the departments of Cauca and Nariño. Although this area is reported in the literature as a new source of gem sapphire, it is interesting to note that it was known and described as early as the 16th century (References – Colombian corundum). The aim of this study is to analyse the gemmological properties, chemistry, and spectrometry, of these recently gathered Colombian corundums and demonstrate that if a basaltic origin dominates, non basaltic corundums coexist. Unfortunately, their characteristics being similar to corundums from other geographic origins, presently they cannot be separated.