When sourcing High Purity Silica (SiO2), the most critical factor is the purity level, typically required to be 99.9% or higher for industrial applications. You must verify the impurity profile, specifically the levels of Iron (Fe), Aluminum (Al), and Titanium (Ti), which are usually measured in parts per million (ppm). Additionally, pay close attention to particle size distribution (D50/D90) and morphology (spherical vs. angular), as these directly impact the flowability and reactivity in applications like semiconductor manufacturing or optical glass production.