Refs.) Mineralogy of Pennsylvania-1922; Samuel S. Gordon . p. 163. Mineralogy of Pennsylvania-1875 ; F. A. Genth; . pp. B.3, 4.B
Old Lead mine where the mineral deposit occured as calcite-rich fracture fillings in Triassic shales and argillites of the lower Lockatong formation. Located on the North branch of Neshaminy Creek, about 3 1/2 mile N. W. of Doylestown, featuring multiple openings on both sides of the creek (abandoned).
Galena from this deposit is both auriferous and argentiferous. The assay for Gold in Galena, conducted in the latter part of the 19th Century, showed the presence of 2 1/4 grains per ton (0.0026 troy oz.), then valued at about $0.10 (current value aprox. $1.88* - $1.75** per ton). The speck of Gold which was extracted from the five ounces of Galena in this assay was placed on exhibit in the cabinet of the U. S. Mint in Philadelphia. F. A. Genth's assays for Silver from Galena, also conducted in the latter part of the 19th Century, yielded 10 to 15 oz. per ton.
The presence of a small amount of gold shouldn’t be surprising because the sedimentary country rock hosting the ore deposit was organic-rich. Gold is usually leached and transported as a bisulphide complex, Au(HS)- . Bisulphide requires a moderately reducing, neutral to mildly alkaline environment, conditions that would be expected in the Lockatong formation.
NOTE: The recovery of Gold in Pennsylvania is fairly rare. The economic impact of gold recovery at New Britain was in essence, negligible. The undue level of attention payed to the auriferous nature of the Galena deposits at this mine is more likely due to the overall rarity of gold recovery in the state (and possibly even represents the encouragements of the 2nd Geological Survey of 1875 to bolster hopes of possible future gold recovery within it's borders [postulation, MRH]).
*Value approximated by using estimated value of gold per oz., averaged over period 1994 to 2004. (Ref. National Mining association.org)
**Value approximated by using estimated value of U.S. Dollar, comparing year 1875 to 2005, using the Consumer Price Index (Ref. EH.net comparison tool)
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Map Reference: 40°19'37"N , 75°11'18"W
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