pyroxene

Stillwater Complex (Neoarchean, 2.71 Ga; near the Stillwater Mine, Beartooth Mountains, Montana, USA) 40
by James St. John

Wind-rippled sand (Oregon Dunes, Florence, Oregon, USA) 14
by James St. John

Black Rock (Pleistocene olivine orendite lamproite volcanic center in the Leucite Hills, Wyoming, USA) 19
by James St. John

Triodia sp. (spinifex grass) (Mt. Scott Range, South Australia) 6
by James St. John

Folded metabentonite in silicate-rich marble (Gouverneur Marble, Mesoproterozoic, ~1.1 Ga; Route 11 roadcut southwest of Canton, New York State, USA) 8
by James St. John

Folded metabentonite in silicate-rich marble (Gouverneur Marble, Mesoproterozoic, ~1.1 Ga; Route 11 roadcut southwest of Canton, New York State, USA) 9
by James St. John

Folded metabentonite in silicate-rich marble (Gouverneur Marble, Mesoproterozoic, ~1.1 Ga; Route 11 roadcut southwest of Canton, New York State, USA) 1
by James St. John

Chromitite in serpentinite (Neoarchean; Red Lodge Chromite District, Beartooth Mountains, Montana, USA) 6
by James St. John

Chromitite with serpentinite (Neoarchean; Red Lodge Chromite District, Beartooth Mountains, Montana, USA) 1
by James St. John

Inch-scale layering of plagioclase feldspar and pyroxene (Stillwater Complex, Neoarchean, 2.71 Ga; near the Stillwater Mine, Beartooth Mountains, Montana, USA) 128
by James St. John

Inch-scale layering of plagioclase feldspar and pyroxene (Stillwater Complex, Neoarchean, 2.71 Ga; near the Stillwater Mine, Beartooth Mountains, Montana, USA) 119
by James St. John

Folded metabentonite in silicate-rich marble (Gouverneur Marble, Mesoproterozoic, ~1.1 Ga; Route 11 roadcut southwest of Canton, New York State, USA) 5
by James St. John

Stillwater Complex (Neoarchean, 2.71 Ga; near the Stillwater Mine, Beartooth Mountains, Montana, USA) 39
by James St. John

Black Rock (Pleistocene olivine orendite lamproite volcanic center in the Leucite Hills, Wyoming, USA) 8
by James St. John

Spinifex komatiite sills in cumulate komatiite lava flow (Upper Komatiitic Unit, Kidd-Munro Assemblage, Neoarchean, 2.711-2.717 Ga; Pyke Hill, near the Potter Mine, east of Timmins, Ontario, Canada) 5
by James St. John

Llao Rock (Crater Lake Caldera, Oregon, USA) 14
by James St. John

Orendite lamproite (Pleistocene, 1.30-1.37 Ma; Black Rock volcanic center, Leucite Hills, Wyoming, USA) 5
by James St. John

Stillwater Complex (Neoarchean, 2.71 Ga; near the Stillwater Mine, Beartooth Mountains, Montana, USA) 44
by James St. John

Wyomingite (Pleistocene, 950-960 ka; Zirkel Mesa, Leucite Hills, Wyoming, USA) 7
by James St. John

Black Rock (Pleistocene olivine orendite lamproite volcanic center in the Leucite Hills, Wyoming, USA) 22
by James St. John

Spinifex metakomatiite (modern fluvial clast) (Raccoon Creek, Granville, Ohio, USA) 5
by James St. John

Folded metabentonite in silicate-rich marble (Gouverneur Marble, Mesoproterozoic, ~1.1 Ga; Route 11 roadcut southwest of Canton, New York State, USA) 7
by James St. John

Black Rock (Pleistocene olivine orendite lamproite volcanic center in the Leucite Hills, Wyoming, USA) 7
by James St. John

Serpentinite (Neoarchean; Red Lodge Chromite District, Beartooth Mountains, Montana, USA) 4
by James St. John

Black Rock (Pleistocene olivine orendite lamproite volcanic center in the Leucite Hills, Wyoming, USA) 9
by James St. John

Serpentinite (Neoarchean; Red Lodge Chromite District, Beartooth Mountains, Montana, USA) 15
by James St. John

Spinifex metakomatiite (modern fluvial clast) (Raccoon Creek, Granville, Ohio, USA) 2
by James St. John

Dune slip face (Oregon Dunes, Florence, Oregon, USA) 6
by James St. John

Black Rock (Pleistocene olivine orendite lamproite volcanic center in the Leucite Hills, Wyoming, USA) 23
by James St. John

Mount Hood Volcano (Cascade Range, Oregon, USA) 14
by James St. John

Boulder of orendite lamproite (Pleistocene, 1.30-1.37 Ma; Black Rock volcanic center, Leucite Hills, Wyoming, USA) 7
by James St. John

Chromite band in serpentinite (Neoarchean; Red Lodge Chromite District, Beartooth Mountains, Montana, USA) 1
by James St. John

Black Rock (Pleistocene olivine orendite lamproite volcanic center in the Leucite Hills, Wyoming, USA) 18
by James St. John

Inch-scale layering of plagioclase feldspar and pyroxene (Stillwater Complex, Neoarchean, 2.71 Ga; near the Stillwater Mine, Beartooth Mountains, Montana, USA) 114
by James St. John

Triodia sp. (spinifex grass) (Mt. Scott Range, South Australia) 1
by James St. John

Inch-scale layering of plagioclase feldspar and pyroxene (Stillwater Complex, Neoarchean, 2.71 Ga; near the Stillwater Mine, Beartooth Mountains, Montana, USA) 116
by James St. John

Sand grains saltating over a dune crest (Oregon Dunes, Florence, Oregon, USA) 1
by James St. John

Slopes of Boar's Tusk (Early Pleistocene wyomingite volcanic center in the Leucite Hills, Wyoming, USA) 3
by James St. John

Inch-scale layering of plagioclase feldspar and pyroxene (Stillwater Complex, Neoarchean, 2.71 Ga; near the Stillwater Mine, Beartooth Mountains, Montana, USA) 115
by James St. John

Wyomingite with xenolith (Pleistocene, 950-960 ka; Zirkel Mesa, Leucite Hills, Wyoming, USA) 7
by James St. John

Inch-scale layering of plagioclase feldspar and pyroxene (Stillwater Complex, Neoarchean, 2.71 Ga; near the Stillwater Mine, Beartooth Mountains, Montana, USA) 109
by James St. John

Inch-scale layering of plagioclase feldspar and pyroxene (Stillwater Complex, Neoarchean, 2.71 Ga; near the Stillwater Mine, Beartooth Mountains, Montana, USA) 113
by James St. John

Black Rock (Pleistocene olivine orendite lamproite volcanic center in the Leucite Hills, Wyoming, USA) 3
by James St. John

Inch-scale layering of plagioclase feldspar and pyroxene (Stillwater Complex, Neoarchean, 2.71 Ga; near the Stillwater Mine, Beartooth Mountains, Montana, USA) 127
by James St. John

Black Rock (Pleistocene olivine orendite lamproite volcanic center in the Leucite Hills, Wyoming, USA) 20
by James St. John

Folded metabentonite in silicate-rich marble (Gouverneur Marble, Mesoproterozoic, ~1.1 Ga; Route 11 roadcut southwest of Canton, New York State, USA) 25
by James St. John

Triodia sp. (spinifex grass) (Mt. Scott Range, South Australia) 5
by James St. John

Inch-scale layering of plagioclase feldspar and pyroxene (Stillwater Complex, Neoarchean, 2.71 Ga; near the Stillwater Mine, Beartooth Mountains, Montana, USA) 108
by James St. John

Metabentonite in silicate-rich marble (Gouverneur Marble, Mesoproterozoic, ~1.1 Ga; Route 11 roadcut southwest of Canton, New York State, USA) 42
by James St. John

Wyomingite (Pleistocene, 950-960 ka; Zirkel Mesa, Leucite Hills, Wyoming, USA) 44
by James St. John

Wyomingite with xenolith (Pleistocene, 950-960 ka; Zirkel Mesa, Leucite Hills, Wyoming, USA) 4
by James St. John

Matthews Hill (wyomingite lamproite volcanic center in the Leucite Hills, Wyoming, USA) 7
by James St. John

Re-exhumed sub-fossil tree (died late 1700s) (Sandy River, Oxbow Park, Oregon, USA) 31
by James St. John

Spinifex metakomatiite (modern fluvial clast) (Raccoon Creek, Granville, Ohio, USA) 1
by James St. John

Inch-scale layering of plagioclase feldspar and pyroxene (Stillwater Complex, Neoarchean, 2.71 Ga; near the Stillwater Mine, Beartooth Mountains, Montana, USA) 118
by James St. John

Basalt (Columbia River Flood Basalt, Miocene, ~15-17 Ma; Mud Hollow, Oregon, USA)
by James St. John

Rumurutiite (North West Africa 13518 Meteorite) (Algeria) 3
by James St. John

Black Rock (Pleistocene olivine orendite lamproite volcanic center in the Leucite Hills, Wyoming, USA) 24
by James St. John

Matthews Hill (wyomingite lamproite volcanic center in the Leucite Hills, Wyoming, USA) 6
by James St. John

Matthews Hill (wyomingite lamproite volcanic center in the Leucite Hills, Wyoming, USA) 9
by James St. John