Buyers must prioritize the Purity Percentage (e.g., 99.9%, 99.99%, or 99.999%) as even trace impurities can drastically alter electrical conductivity or chemical reactivity. Always request a Certificate of Analysis (COA) and a GDMS (Glow Discharge Mass Spectrometry) report to identify specific impurity elements in parts per million (ppm) or parts per billion (ppb). Additionally, specify the Physical Form required, such as ingots, pellets, wire, or sputtering targets, to ensure compatibility with your production machinery.