Outer portion of the vein containing considerable tellurium, and high values in copper, gold, and silver; specimen is from Commercial mine. Salt Lake county, Utah, 1900.

Sulphide enrichment. A central band of cupriferous pyrite (P) containg a trace of tellurium and low values in copper, gold, and silver, is inclosed by bands of chalcocite (C) and tenorite, forming the outer portion of the vein containing considerable tellurium, and high values in copper, gold, and silver. Specimen is from Commercial mine. Natural size. Speciment 220. Salt Lake county, Utah, 1900, in false color as plate 38c in U.S. Geological Survey. Professional paper 38. 1905.