Show mineralogy OF NATIONAL miner national nev the miner is greatly indebted to carlos aquillar a chemist and mineralogist well known to western ms mining ning men for the following on the mineralogy of national ores it is in explanation of terms used by dr frank L hess geologist of the united states geological survey in describing specimens of ores from national as published in a recent issue of the miner this explanation of technical terms by mr aquilar will be of help to prospectors and others lacking technical knowledge an explanation of minerals riot touched on by dr hess is also given in touching upon this phase mr aquilar says it must not be inferred that even these additional addition al minerals by any means exhaust the list of 0 precious mineral contained in the wonderful ore zone of national electrum of the national district dr hess describes in a recent article as a natural alloy of gold and silver in a matrix or quartz in the proportion of two parts of gold and one part of silver or gold 65 silver 35 percentages respectively with separate crystals of native gold and of native silver commonly called gray copper and also known to mineralogists as fal herz is of very common mccurr occurrence ance in the national district and is one of the chief constituents accompanying the rich ores of goldfield nev as noted by F L hansome in professional paper no 66 united states geological survey while a great deal of the cripple creek ores are also accompanied by gray copper it usually occurs massive granular or compact and when crystallized it occurs in isometric tetrahedral four a angled n aled crystals from which fact it derives its name its color ranges from steel gray to iron black it has a conc holdal shell like uneven fracture ranges in hardness from 3 to 45 and can be scratched by a knife is in composition essentially senti ally a sulphide of copper and antimony but the sulphide of antimony is at times partially replaced by the sulphide of arsenic or of bismuth or both of them and the of copper may be partially replaced by silver sulphide thus accounting for the high silver values found in ores of this character at national another ore mentioned in the article reproduced in the miner is commonly known as brittle silver and is iron gray to nearly black in color with a metallic lustre it usually occurs massive and is essentially an carrying when pure per cent antimony per cent sulphur and per cent silver is also a sulphide or of silver and antimony but contains a lower percentage of silver than generally about per cent or ruby silver is also of common occurrence in the national ores and its composition equals per cent sulphur per cent antimony and per cent silver this mineral is dark red to almost black in color with a vitreous or glossy to adamantine luster or light ruby silver is nearly the same as in composition but with arsenic replacing much or all of the antimony in conclusion it might be stated that gold is found with all the silver metals mentioned in the national district this being chiefly a gold camp the superficial silver values so abundant over the entire district being replaced as depth is attained |