Weekly journal-miner., 1910-06-15
FALSE REFERENCES.

One often hears of broad veins of ere that somehow do not turn out to be productive. The remarkable claims made or a vein, if well foun- ed, would seem to call for produc- tive results, but it sometimes hap pens that the claims made are based upon ineonclusive evidence, and this accounts for the failure that follows It may be that the mine operator deceives himself through ignorance, or it may be that he desires a false inference to be spread concerning the worth of his mineral showing. The Salt Lake Mining Review calls attention to the error that is likely to inhere in an "average sample" of a vein, something that sounds well, but in reality may a very dangerous thing to follow. In sam bling across the face of a shoot, the punching of the. selected ore for the purpose of securing one assay for the whole width is certain to be in exact if the naturalization is very irregular. The proper method is to assay each sample taken across the face, thus revealing the real nature of the enrichment. Tie Mining Re view comments as follows:
 "In the matter of average sam ples mine owner is., apt to be mis- led as to the true value of his prop erty, and great many operators, taking such tests at their face value are liable to meet with some hard and disappointing propositiOns if they are governed by them. For instance, a large body of ore is uncovered in which occur streaKs and zones of pay mineral, associated with shoots of vein matter carrying but little values. An average sample is made clear across the. Vein with results that are most encouraging. The pay streak is possibly two feet in width, assaying $50 to the ton; while the whole vein, ten feet in width, aver ages $75. This looks good to the owner of the mine, and he goes ahead with its development and equipment, laboring under the i'm pression that he mas ten-foot vein of $75 ore; when, as a matter of fact, he has only two feet of ore which it will pay him to handle, the ether eight feet being little better than slightly mineralized rock Rock that cannot be handled at a profit under any circumstances, and rock which, if mixed with the pay pro- duct of the mine, reduces its grade without in the least increasing its value. The fact that the full ten feet of ore averages $75 to the ton really amounts to: nothing, and is a detriment, hardship, without ques- tion of doubt, to, the really good ore in the mine, and does not give fair and accurate idea of. the value of | the ore body. @
 "NO man would mix barren eoun- try rock with the ore he is shipping i to the market or to the shelter; and | yet ne might as well do so as to mine or mill with high grade ore, mineral so low in grade that it can not be handled at profit on it's own merits; on its own intrinsic value. As a matter of fact, the eight feet of vein material would go only a little in excess of s a ton, and this would not pay shipping and smelling or milling charges; and, therefore, is valueless excepting in the matter of tonnage"
 There is a good deal of laxness or perversity shown in the statements made concerning the degree of min eralizatiOn in ore shoots, and it is well that one fruitful source of CT TOT Or fale inference should be made clear to the novice.