Crystal Mine

Crystal Mine is located near Juneau in the U.S. state of Alaska. The quartz ledge at the Crystal Mine was first discovered in 1895 by B. Heins. It was so named because of the large pyrite cubes which were found occurring in the surface outcrops of the ledge. Gold was extracted till 1905 from quartz using ten-stamp mill and from about 1,000 feet of underground workings yielded 1,210 ounces of gold. Intermittent production of gold is reported till 1925 but there are no records of the yield. The formation was determined as of 54 to 56 Ma age. The gold yielding resources available from the mine were assessed as 9,000 tons of material with yield of 0.21 ounce of gold per ton.GeographyOn the sides of many of the pyrite cubes, small particles and crystals of gold may be observed, and this somewhat novel occurrence makes the ore of special mineralogic interest. The mine workings were situated from the wharf at Snettisham and above high tide water. The ledge has a width of from 1-, averaging about, and is exposed for over in length. Fragments of the enclosing andesite are often included in the vein, and these as well as the quartz carry the gold values.