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| Keywords: The Quarterly journal of the Geological Society of London (12895417644).jpg 1864 <br> BLAKE NEVADA TERRITORY <br> Fig 4 Section of the Comstock Lode <br> 325 <br> w <br> It is divided into two portions at the level by a porphyritic mass <br> or horse which will probably thin out in depth and the two <br> parts of the vein will then become united in one The walls on <br> each side are compact porphyry of an olive or greyish -green colour <br> mottled with white and charged in many places with iron-pyrites <br> The eastern part of the vein which for the past year has been <br> most worked is 30 feet wide at the lower level and consists of <br> white granular quartz so complely shattered or broken up that it <br> may be crumbled with the hand and requires to be carefully sup- <br> ported by timbers as the excavations progress Portions of it are <br> in a sandy or powdered state and are traversed or intermingled <br> with harder and more compact masses and with a greenish por- <br> phyritic rock like that of the central mass or horse <br> This great mass of friable quartz is traversed in almost every <br> direction by veins or streaks of the richest sulphurets of silver both <br> brittle and sectile and with free gold in irregular ragged grains <br> These veins or masses seldom reach a thickness of more than two or <br> three inches and are often merely crusts or coatings or seams in <br> the quartz and are from one-tenth to one-eighth of an inch thick <br> It is more common to find the silver ore ramified irregularly through <br> the broken quartz holding it together and bearing the imprint of the <br> flat surfaces of the irregularly crystalline mass Galena and copper- <br> pyrites with white iron-pyrites are associated with these sulphurets <br> In some of these irregular veins and in cavities connected with them <br> beautiful crystals of stephanite the brittle sulphuret of silver occur <br> I also found one single fragment of ruby silver with the stephanite <br> but it is very rare Filaments of native silver are frequently found ; <br> but in this soft ore gold is the most generally diffused metal 36089588 111261 51125 Page 325 Text v 20 http //www biodiversitylibrary org/page/36089588 1864 Geological Society of London Biodiversity Heritage Library The Quarterly journal of the Geological Society of London v 20 1864 Geology Periodicals Smithsonian Libraries bhl page 36089588 dc identifier http //biodiversitylibrary org/page/36089588 smithsonian libraries Information field Flickr posted date ISOdate 2014-03-03 Check categories 2015 August 26 CC-BY-2 0 BioDivLibrary https //flickr com/photos/61021753 N02/12895417644 2015-08-26 16 51 07 cc-by-2 0 PD-old-70-1923 The Quarterly journal of the Geological Society of London 1864 Photos uploaded from Flickr by FĂŚ using a script | ||||
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