High-purity quartz products are categorized into four grades based on SiO2 purity: ultra-high purity (ω(SiO2) ≥ 99.998% or 4N8), high-purity (ω(SiO2) ≥ 99.995% or 4N5), medium-purity (ω(SiO2) ≥ 99.99% or 4N), and standard-purity (ω(SiO2) ≥ 99.9% or 3N).
They are pretty different:
you telling me that i can buy standard-purity high-purity quartz? thats fucked up