Mar 11, 2013 ... I wonder if these are pieces of ore used for really early copper extraction. Does this exist, an iron/copper mineral? Or is this some kind of slag from this procedure? Or could they have been used as firestarters incombination with a flint stone?... Or could this be more recent and something completely different...
Copper slag is a by-product of copper extraction by smelting. During smelting, impurities become slag which floats on the molten metal. Slag that is quenched in water produces angular granules which are disposed of as waste or utilized as discussed below.
Nov 8, 2017 ... Within the United States, mining and production of copper are primarily located in the West, specifically Arizona, New Mexico, Utah, Nevada and .... More information about copper mining and production slag can be found in the EPA's Report to Congress on Special Wastes from Mineral Processing.
Coal slag, 2.7. Cobalt, 8.92. Copper, cast-rolled, 8.8 - 8.95. Copper ore, pyrites, 4.1 - 4.3. Diamond, 2.26. Dolomite, 2.9. Dysprosium, 8.55. Erbium, 9.066. Europium ... Iron, ore, limonite, 3.6 - 4.0. Iron ore, magnetite, 4.9 - 5.2. Iron ore, specular, 5.4. Iron slag, 2.5 - 3.0. Lanthanum, 6.17. Lead, 11.34. Lead ore, galena, 7.3 - 7.6.