0.307 ppm Au + 94 ppm Cu + 1.29 ppm Ag (siliceous shale) OREAS 264 - 60g

OREAS 264 was prepared from oxide heap leach material sourced from the Goldstrike operation in Eureka County in north-eastern Nevada. The mining operation is located on the Carlin Trend and owned by Nevada Gold Mines (operated by Barrick).
Thirty-one commercial analytical laboratories participated in the program to certify the elements shown below. The following methods were employed:

• Gold by fire assay (15-40g charge weight) with AAS, ICP-OES or ICP-MS finish (31 laboratories);
• Gold by aqua regia digestion (15-50g sample weight) with ICP-MS, AAS or ICP-OES finish (22 laboratories);
• Gold by cyanide leach (20-200g) via a variety of cyanide leach methods (LeachWELL tablets, alkaline added sodium cyanide solution and sodium cyanide liquor with LeachWELL powder) with ICP or AAS finish (20 laboratories);
• Gold by x-ray photon assay on ~350g sample weights using 4 Chrysos PhotonAssay machines at 3 laboratories. Multiple rounds of data (comprising three or six replicates) were generated by different staff from 3 of the machines;
• Full ICP-OES and ICP-MS elemental suites by aqua regia digestion (up to 25 laboratories depending on the element);
• Full ICP-OES and ICP-MS elemental suites by 4-acid (HNO3-HF-HClO4-HCl) digestion (up to 25 laboratories depending on the element).