River Cobble (Gneiss/Migmatite)
Gneissic Metamorphic Rock (composed mainly of Quartz, Feldspar, and Biotite)
metamorphic
Category
Sedimentary Rock (Specifically A Clastic Sedimentary Rock Formed Into A Cobble)
Browse sedimentary rock (specifically a clastic sedimentary rock formed into a cobble) specimens identified by the Rock Identifier community.
Red Sandstone
Arenite with Hematite cementation
sedimentary
Dalmatian Jasper / Dalmatian Stone
Peralkaline Rock (Silicon Dioxide with Amphibole inclusions)
igneous
Granite Cobble
Granite (Phaneritic Quartz-Feldspar-Mica intrusive rock)
igneous
Sandstone Concretion
Sedimentary concretion
Sedimentary
Pink Granite
Phaneritic Felsic Igneous Rock (composed primarily of K-feldspar, Quartz, and Biotite)
igneous
Fish Fossil in Limestone
Lycoptera (likely) in Micritic Limestone
sedimentary
Quartzite Pebbles (River Stones)
Quartzite (primarily Silicon Dioxide, SiO2)
metamorphic
Veined Pebble (likely a Quartz-Veined Pebble)
Pebble with Mineral Vein (e.g., Quartz Vein in a Chert/Mudstone Pebble)
Sedimentary Rock (possibly conglomerate or breccia with a quartz vein)
Flowerstone (Porphyry)
Porphyritic Andesite or Basalt
igneous
Quartzite
Quartzite (primarily SiO2)
metamorphic
Granite Cobble
Plutonic Granite
igneous
Quartzite Pebble
Metamorphic Quartz (SiO2)
metamorphic
Quartz (Druzy)
Silicon Dioxide (SiO2)
mineral
River Quartzite (or Quartz Cobble)
Quartzite (primarily Silicon Dioxide - SiO2)
metamorphic
Chalcedony (Agate/Jasper mix in host rock)
Chalcedony (cryptocrystalline Silicon Dioxide, SiO2)
mineral
Sandstone
Arenite
sedimentary
Geode with Quartz and possibly Jasper/Hematite
Quartz (SiO2) and Chalcedony (cryptocrystalline SiO2), possibly stained by iron oxides
Mineral/Sedimentary Geode
Quartzite
Metamorphic Quartz (SiO2)
metamorphic
Hag Stone
Perforated Sedimentary Rock
sedimentary
Puddingstone (specifically Gowganda Tillite or St. Joseph Island Puddingstone)
Jasper Conglomerate
sedimentary
Fossiliferous Limestone
CaCO3 (principally Calcite or Aragonite)
sedimentary
Red Sandstone
Arenite (ferruginous sandstone)
sedimentary
Pink Granite
Granite (Felsic Plutonic Rock)
igneous
Serpentine
Antigorite/Lizardite (Mg,Fe)3Si2O5(OH)4
metamorphic
Labradorite
(Ca, Na)(Al, Si)4O8
mineral
Basalt
Basalt (Mafic volcanic rock)
igneous
Pink Granite (Potassium-rich)
Phaneritic Felsic Igneous Rock (K-Feldspar Granite)
igneous
Garnet Schist
Garnetiferous Micaceous Schist
metamorphic
Quartzite
Quartzite (primarily SiO2)
metamorphic
Chert (Yellow Jasper/Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Quartzite
Quartzite (primarily SiO2)
metamorphic
Red Sandstone
Arenite (with Iron Oxide / Hematite cementation)
sedimentary
Granite Cobble
Granite (Felsic Intrusive)
igneous
Glacial Erratic (Sandstone/Quartzite)
Glacial Erratic specimen (likely Orthoquartzite or Feldspathic Sandstone)
sedimentary or metamorphic
Quartzite (Water-worn Cobble)
Quartzite (Composition: 90%+ SiO2)
metamorphic
Unakite
Epidotized Granite
metamorphic
Agate
Silicon Dioxide (SiO2)
mineral
Granite Cobble
Phaneritic Felsic Igneous Rock
igneous
Granite Cobble
Granite (Phaneritic Igneous Rock)
igneous
Quartzite with Iron Staining
Silicon Dioxide (SiO2) with Fe2O3 impurities
metamorphic
Chert (Jasper/Common Opal mix)
Microcrystalline Quartz (SiO2)
sedimentary