Bulletin . 24 CALIFORNIA STATE MINING BUREAU. While, as described above, the forms of quicksilver ore-bodies do notdiffer essentially from the forms known and recognized in the cases ofthe other precious and semi-precious metals, they do differ in one veryimportant feature—that of depth. As is noted in preceding para-graphs^^, the most famous quicksilver mines of the world, Almaden,(Spain), Idria, (Austria), New Almaden and New Idria in California,have been worked to depths of only 1300, 1000, 2450 and 1060respectively; and with the exception of the first-named have all appar-ently bottomed th
Bulletin . 24 CALIFORNIA STATE MINING BUREAU. While, as described above, the forms of quicksilver ore-bodies do notdiffer essentially from the forms known and recognized in the cases ofthe other precious and semi-precious metals, they do differ in one veryimportant feature—that of depth. As is noted in preceding para-graphs^^, the most famous quicksilver mines of the world, Almaden,(Spain), Idria, (Austria), New Almaden and New Idria in California,have been worked to depths of only 1300, 1000, 2450 and 1060respectively; and with the exception of the first-named have all appar-ently bottomed their ore-bodies. In California, but few of the quick-silver mines have been worked to depths greater than 500 feet belowtheir outcrops. The superficial nature of quicksilver ore deposits ismore fully realized, when we consider the fact that many gold andcopper mines, the world over, are being profitably worked at depthsexceeding 2000 feet, and some even down to nearly 6000 feet. 2=See p. 21. PLATE IV.
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