An Aroostook County mountain laced with gold, silver and other metals potentially worth billions of dollars will again be the center of attention when the contentious debate over Maine’s stringent mining regulations begins anew in Augusta next week. Aroostook’s Bald Mountain, however, isn’t the only location in Maine with valuable, potentially extractable minerals. The Maine Geological Survey lists 10 sites of “significant known metallic mineral deposits” in the state, scattered from Warren in midcoast Maine to the state’s mountainous western border and Bald Mountain in the north.