In coarse-gold quartz vein systems, standard 30g or 50g fire assay charges are statistically prone to the ‘nugget effect’. A single 0.5mm gold flake in one split can report 50 g/t Au, while an identical split from the same interval reports 0.2 g/t Au.
How Metallic Screening Solves the Dilemma
RVA Laboratories’ Metallic Screen Fire Assay (SCR-FA-05) processes an entire 1,000g sample. By sieving through a 106µm screen and assaying the coarse fraction (+106µm) to extinction while running duplicate assays on the fine fraction (-106µm), we mathematically reconstruct the true representative grade of the mineralized interval.