James St. John: Copper (Mesoproterozoic, 1.05-1.06 Ga; White Pine Mine, Ontonagon County, Michigan, USA) 1
James St. John: Native copper-replaced cross-bedded sedimentary rocks (Nonesuch Shale, Mesoproterozoic; White Pine Mine, Upper Peninsula of Michigan, USA) 1
James St. John: Native copper-replaced cross-bedded sedimentary rocks (Nonesuch Shale, Mesoproterozoic; White Pine Mine, Upper Peninsula of Michigan, USA) 2
James St. John: Native copper-replaced cross-bedded sedimentary rocks (Nonesuch Shale, Mesoproterozoic; White Pine Mine, Upper Peninsula of Michigan, USA) 3
James St. John: Native copper-replaced cross-bedded sedimentary rocks (Nonesuch Shale, Mesoproterozoic; White Pine Mine, Upper Peninsula of Michigan, USA) 4
James St. John: Native copper-replaced cross-bedded sedimentary rocks (Nonesuch Shale, Mesoproterozoic; White Pine Mine, Upper Peninsula of Michigan, USA) 5
James St. John: Native copper-replaced cross-bedded sedimentary rocks (Nonesuch Shale, Mesoproterozoic; White Pine Mine, Upper Peninsula of Michigan, USA) 6
James St. John: Copper sheet (Mesoproterozoic, 1.05-1.06 Ga; White Pine Mine, Ontonagon County, Upper Peninsula of Michigan, USA) 1
James St. John: Copper sheet (Mesoproterozoic, 1.05-1.06 Ga; White Pine Mine, Ontonagon County, Upper Peninsula of Michigan, USA) 2
James St. John: Copper sheet (Mesoproterozoic, 1.05-1.06 Ga; White Pine Mine, Ontonagon County, Upper Peninsula of Michigan, USA) 3
James St. John: Copper sheet (Mesoproterozoic, 1.05-1.06 Ga; White Pine Mine, Ontonagon County, Upper Peninsula of Michigan, USA) 4
James St. John: Copper (Mesoproterozoic, 1.05-1.06 Ga; White Pine Mine, Ontonagon County, Michigan, USA) 2
James St. John: Native copper in sandstone (Nonesuch Formation, Mesoproterozoic; White Pine, Upper Peninsula of Michigan, USA) 1
James St. John: Native copper in sandstone (Nonesuch Formation, Mesoproterozoic; White Pine, Upper Peninsula of Michigan, USA) 2
James St. John: Carbonaceous shale mineralized with microscopic chalcocite (Nonesuch Formation, Mesoproterozoic; Upper Peninsula of Michigan, USA) 1
James St. John: Carbonaceous shale mineralized with microscopic chalcocite (Nonesuch Formation, Mesoproterozoic; Upper Peninsula of Michigan, USA) 2
James St. John: Black lacustrine mudshale (Nonesuch Shale, Mesoproterozoic, ~1.07-1.08 Ga; White Pine Mine area, Upper Peninsula of Michigan, USA) 1
James St. John: Black lacustrine mudshale (Nonesuch Shale, Mesoproterozoic, ~1.07-1.08 Ga; White Pine Mine area, Upper Peninsula of Michigan, USA) 2
James St. John: Black lacustrine mudshale (Nonesuch Shale, Mesoproterozoic, ~1.07-1.08 Ga; White Pine Mine area, Upper Peninsula of Michigan, USA) 3
James St. John: Black lacustrine mudshale (Nonesuch Shale, Mesoproterozoic, ~1.07-1.08 Ga; White Pine Mine area, Upper Peninsula of Michigan, USA) 4
James St. John: Black lacustrine mudshale (Nonesuch Shale, Mesoproterozoic, ~1.07-1.08 Ga; White Pine Mine area, Upper Peninsula of Michigan, USA) 5
James St. John: Black lacustrine mudshale (Nonesuch Shale, Mesoproterozoic, ~1.07-1.08 Ga; White Pine Mine area, Upper Peninsula of Michigan, USA) 6
James St. John: Black lacustrine mudshale (Nonesuch Shale, Mesoproterozoic, ~1.07-1.08 Ga; White Pine Mine area, Upper Peninsula of Michigan, USA) 7
James St. John: Black lacustrine mudshale (Nonesuch Shale, Mesoproterozoic, ~1.07-1.08 Ga; White Pine Mine area, Upper Peninsula of Michigan, USA) 8
James St. John: Black lacustrine mudshale (Nonesuch Shale, Mesoproterozoic, ~1.07-1.08 Ga; White Pine Mine area, Upper Peninsula of Michigan, USA) 9
James St. John: Black lacustrine mudshale (Nonesuch Shale, Mesoproterozoic, ~1.07-1.08 Ga; White Pine Mine area, Upper Peninsula of Michigan, USA) 10
James St. John: Black lacustrine mudshale (Nonesuch Shale, Mesoproterozoic, ~1.07-1.08 Ga; White Pine Mine area, Upper Peninsula of Michigan, USA) 11
James St. John: Cupriferous black lacustrine mudshale (Nonesuch Shale, Mesoproterozoic, ~1.07-1.08 Ga; White Pine Mine area, Upper Peninsula of Michigan, USA) 1
James St. John: Cupriferous black lacustrine mudshale (Nonesuch Shale, Mesoproterozoic, ~1.07-1.08 Ga; White Pine Mine area, Upper Peninsula of Michigan, USA) 2
James St. John: Cupriferous black lacustrine mudshale (Nonesuch Shale, Mesoproterozoic, ~1.07-1.08 Ga; White Pine Mine area, Upper Peninsula of Michigan, USA) 3