Gold with a specific gravity of 15 to 19.3 and black sand at 5 to 6, when classified to the same mesh size, will allow the gold contained to be easily recovered. Proper classification (sorting by size) is the key to fine gold recovery form black sands. Without classification, gravel three times the size of gold will be recovered with the gold, hence the necessity for proper classification.The black sands are going to have more gold than the lighter colored sands. It is worthwhile to take your time to search for a beach that has nice black sand concentrations. Mining Techniques for Lake Superior Beaches The real challenge with mining on Lake Superior is the fineness of the gold. ItJan 25, 2017 This black sand was very heavy and, in 1870 a number of residents started panning the sand for gold. The mining of beach sand for gold went on for 20 years between Ballina and Southport. Later analysis of the sand found that it contained titanium ores including ilmenite and rutile, with zircon and traces of tin, platinum and monazite.