silicified

Mudshale & ironstone clasts in quartz-pebble conglomerate ("Sharon Conglomerate", Lower Pennsylvanian; Jackson North roadcut, Ohio, USA) 4
by James St. John

Calcite filling a former vug in limestone (Ashlock Formation, Upper Ordovician; Paint Lick Elementary School outcrop, Garrard County, Kentucky, USA)
by James St. John

Mookaite (Windalia Radiolarite Formation, Lower Cretaceous; Western Australia) 17
by James St. John

Coral in fossiliferous limestone (Jeffersonville Limestone, Middle Devonian; Falls of the Ohio, southern Indiana, USA) 31
by James St. John

Opalite-chert with cinnabar (Silver Chief Mine, Battle Mountain, Nevada, USA) 2
by James St. John

Limestone and shale (Ashlock Formation, Upper Ordovician; Route 52 roadcut, near Point Leavell, Kentucky, USA) 9
by James St. John

Mudshale clasts in pebbly sandstone ("Sharon Conglomerate", Lower Pennsylvanian; Jackson North roadcut, Ohio, USA) 66
by James St. John

Cone-in-cone limestone interbed in shales (Ohio Shale, Upper Devonian; Glen Echo Ravine, Columbus, Ohio, USA) 2
by James St. John

Opalite-chert with cinnabar (Silver Chief Mine, Battle Mountain, Nevada, USA) 3
by James St. John

Limestone with chert nodule (Columbus Limestone, Middle Devonian; Mt. Tabor, Ohio, USA) 5
by James St. John

Rugose corals in limestone (Paleozoic) 1
by James St. John

Limestone and shale (Ashlock Formation, Upper Ordovician; Route 52 roadcut, near Point Leavell, Kentucky, USA) 5
by James St. John

Paraspirifer bownockeri (pyritized fossil brachiopod) (Silica Formation, Middle Devonian; quarry in Lucas County, Ohio, USA) 6
by James St. John

Calcite-filled vug in limestone (Ashlock Formation, Upper Ordovician; Route 52 roadcut, near Point Leavell, Kentucky, USA)
by James St. John

Hot Creek Rhyolite Flow (Pleistocene, 288 or 333 ka; Hot Creek Gorge, Long Valley Caldera, California, USA) 20
by James St. John

Fossiliferous limestone (upper Columbus Limestone, Middle Devonian; Marblecliff Quarry, Hilliard, Ohio, USA) 1
by James St. John

Limestone and shale (Ashlock Formation, Upper Ordovician; Route 52 roadcut, near Point Leavell, Kentucky, USA) 6
by James St. John

Quartzite (Kona Dolomite, Paleoproterozoic, 2.2 to 2.3 Ga; Marquette South Outcrop, Upper Peninsula of Michigan, USA)
by James St. John

Kona Dolomite (Paleoproterozoic, 2.1-2.2 Ga; Pelissier Lake Northeast outcrop, south of Marquette, Michigan, USA)
by James St. John

Paraspirifer bownockeri (pyritized fossil brachiopod) (Silica Formation, Middle Devonian; quarry in Lucas County, Ohio, USA) 1
by James St. John

Kona Dolomite (Paleoproterozoic, 2.2 to 2.3 Ga; County Road 480 roadcut, Ragged Hills, Upper Peninsula of Michigan, USA) 1
by James St. John

Weathered-out quartz & quartzite pebbles from conglomerate ("Sharon" Conglomerate, Lower Pennsylvanian; Jackson North roadcut, Ohio, USA) 2
by James St. John

Columbus Limestone (Middle Devonian) (Hayden Run, Dublin, Ohio, USA) 4
by James St. John

White fossiliferous chert nodule in fossiliferous limestone (Columbus Limestone, Middle Devonian; Emerald Parkway roadcut, Dublin, Ohio, USA) 6
by James St. John

Silicified coral fossil (Middle Devonian; Auglaize Quarry, near Junction, Ohio, USA) 1
by James St. John

Gastropod internal mold (Columbus Limestone, Middle Devonian; abandoned quarry, Kelleys Island, Lake Erie, Ohio, USA) 7
by James St. John

Stromatoporoid (Ashlock Formation, Upper Ordovician; Paint Lick Elementary School outcrop, Garrard County, Kentucky, USA) 12
by James St. John

Solitary rugose corals (Marblehead Member, Columbus Limestone, Middle Devonian; lakehore outcrop near Marblehead Lighthouse, Ottawa County, Ohio, USA) 19
by James St. John

Paraspirifer bownockeri (pyritized fossil brachiopod) (Silica Formation, Middle Devonian; quarry in Lucas County, Ohio, USA) 5
by James St. John

Karst & Columbus Limestone (Middle Devonian; Indian Village Canyon, Columbus, Ohio, USA) 10
by James St. John

Fossiliferous limestone (Jeffersonville Limestone, Middle Devonian; Falls of the Ohio, southern Indiana, USA) 12
by James St. John

White fossiliferous chert in limestone (Columbus Limestone, Middle Devonian; Emerald Parkway roadcut, Dublin, Ohio, USA) 4
by James St. John

Agatized coral (Tertiary; Withlacoochee River, Georgia, USA) 17
by James St. John

Stromatoporoid (Ashlock Formation, Upper Ordovician; Paint Lick Elementary School outcrop, Garrard County, Kentucky, USA) 18
by James St. John

Cephalopod in limestone (Jeffersonville Limestone, Middle Devonian; Falls of the Ohio, southern Indiana, USA)
by James St. John

Mudshale clast in quartz-pebble conglomerate ("Sharon Conglomerate", Lower Pennsylvanian; Jackson North roadcut, Ohio, USA) 48
by James St. John

Paraspirifer bownockeri (pyritized fossil brachiopod) (Silica Formation, Middle Devonian; quarry in Lucas County, Ohio, USA) 2
by James St. John

Paraspirifer bownockeri (pyritized fossil brachiopod) (Silica Formation, Middle Devonian; quarry in Lucas County, Ohio, USA) 12
by James St. John

Nautiloid cephalopod (Ashlock Formation, Upper Ordovician; Paint Lick Elementary School outcrop, Garrard County, Kentucky, USA) 4
by James St. John

Stromatolitic metadolostone (Kona Dolomite, Paleoproterozoic, 2.2 to 2.3 Ga; Marquette South Outcrop, Upper Peninsula of Michigan, USA)
by James St. John

Stromatoporoid (Ashlock Formation, Upper Ordovician; Paint Lick Elementary School outcrop, Garrard County, Kentucky, USA) 8
by James St. John

Columbus Limestone (Middle Devonian) (Hayden Run, Dublin, Ohio, USA) 3
by James St. John

Coral in fossiliferous limestone (Jeffersonville Limestone, Middle Devonian; Falls of the Ohio, southern Indiana, USA) 32
by James St. John

Moellerina greenei (fossil charophyte oogonia) in fossiliferous limestone (Columbus Limestone, Middle Devonian; Emerald Parkway roadcut, Dublin, Ohio, USA) 5
by James St. John

Delaware Limestone over Columbus Limestone (Middle Devonian; Indian Village Canyon, Columbus, Ohio, USA) 4
by James St. John

Agatized coral (Tertiary; Withlacoochee River, Georgia, USA) 4
by James St. John

Columbus Limestone (Middle Devonian) (Hayden Falls, Dublin, Ohio, USA) 1
by James St. John

Silicified rugose coral in limestone (Columbus Limestone, Middle Devonian; Quarry Trails Park, Columbus, Ohio, USA) 5
by James St. John

Fossiliferous limestone (Columbus Limestone, Middle Devonian; Emerald Parkway roadcut, Dublin, Ohio, USA) 8
by James St. John

Archaeocyathan limestone (Ajax Limestone, Lower Cambrian; Ajax Mine, South Australia) 31
by James St. John

Favositid coral in fossiliferous limestone (Columbus Limestone, Middle Devonian; Olentangy Indian Caverns, central Ohio, USA) 5
by James St. John

Columbus Limestone (Middle Devonian) (Hayden Run, Dublin, Ohio, USA) 5
by James St. John

Columbus Limestone (Middle Devonian; Wright Run Creek, Dublin, Ohio, USA) 2
by James St. John

Paraspirifer bownockeri (pyritized fossil brachiopod) (Silica Formation, Middle Devonian; quarry in Lucas County, Ohio, USA) 4
by James St. John

Paraspirifer bownockeri (pyritized fossil brachiopod) (Silica Formation, Middle Devonian; quarry in Lucas County, Ohio, USA) 11
by James St. John

Columbus Limestone (Middle Devonian) (Hayden Run, Dublin, Ohio, USA) 7
by James St. John

Hexagonaria (fossil coral) (Columbus Limestone, Middle Devonian; Emerald Parkway roadcut, Dublin, Ohio, USA) 3
by James St. John

Fossiliferous limestone (Columbus Limestone, Middle Devonian; Emerald Parkway roadcut, Dublin, Ohio, USA) 7
by James St. John

Mookaite (Windalia Radiolarite Formation, Lower Cretaceous; Western Australia) 29
by James St. John

Columbus Limestone (Middle Devonian) (Hayden Falls, Dublin, Ohio, USA) 3
by James St. John