Shale (Beach-worn)
Laminated Pelite (primarily clay minerals and quartz)
sedimentary
Category
Not A Rock
Browse not a rock specimens identified by the Rock Identifier community.
Learn about Not A Rock in the encyclopedia
View all →
River Pebble (likely Quartzite or Siltstone)
Sedimentary Clast (SiO2 based)
sedimentary
Painted River Rock
Painted Quartzite or Smooth Siltstone
sedimentary
Granite
Granite
Igneous
Unidentified Rock Fragment
Unknown
Rock
Unknown Tumbled Stone
Unknown (Too Blurry)
mineral
Quartz Geode
Silicon Dioxide (SiO2) within a sedimentary or volcanic shell
mineral
Quartz Geode
Silicon Dioxide (SiO2)
mineral
Basalt with Alteration Crust
Basalt (SiO2 range 45-52%)
igneous
Leopard Skin Jasper
Orbicular Jasper (Silicon Dioxide, SiO2)
sedimentary
Basalt
Mafic Igneous Rock (composed primarily of plagioclase feldspar and pyroxene)
Igneous
Basalt
Basalt (Mafic volcanic rock)
igneous
Basalt River Cobble
Basalt (Mafic volcanic rock)
igneous
Basalt Cobble
Aphanitic Mafic Igneous Rock (Basalt)
igneous
Milky Quartz with Chlorite Schist Inclusions
Quartz (SiO2) with Chlorite Group silicates (typically (Mg,Fe)3(Si,Al)4O10(OH)2)
metamorphic
Granite
Phaneritic Igneous Rock (primarily Quartz, Feldspar, Mica)
igneous
Pebble (likely Sandstone or Granitic Pebble)
Clastic Sediment (or specific rock type, e.g., Arenite, Granitoid Pebble)
Rock (likely Sedimentary)
Druzy Quartz on Chert/Siltstone
Silicon Dioxide (SiO2) on Microcrystalline Silica/Siltstone matrix
sedimentary
Quartz Druzy (Geode Fragment)
Silicon Dioxide (SiO2)
mineral
Orange Quartz (or Carnelian Chalcedony)
Silicon Dioxide (SiO2)
mineral
Basalt
Basalt (composition predominately Plagioclase feldspar and Pyroxene)
igneous
River Rocks (Black)
Various lithologies (e.g., basalt, chert, obsidian for black varieties), mechanically rounded clasts
Sedimentary
Herkimer Diamond
Quartz (Silica - SiO2)
mineral
Quartz Vein in Host Rock
Hydrothermal Quartz (SiO2) in Slates/Schists
metamorphic
Banded Greywacke
Greywacke (Lithic wacke)
sedimentary
Dyed Quartzite
Metamorphosed Quartz (SiO2) with synthetic pigment
metamorphic
Granite
Plutonic felsic rock (Quartz, Feldspar, Mica)
igneous
Basalt
Extrusive mafic igneous rock
igneous
Slate
Foliated Metamorphic Rock (Mainly composed of Quartz, Illite, Chlorite)
metamorphic
Sandstone (Weathered Cobble)
Clastic sedimentary rock (primarily SiO2)
sedimentary
Vuggy Quartz on Matrix
Crystalline Silicon Dioxide (SiO2)
mineral
Serpentine
Antigorite/Lizardite/Chrysotile group, Mg3Si2O5(OH)4
metamorphic
Pink Granite
Phaneritic Felsic Igneous Rock (composed primarily of Quartz and Potassium Feldspar)
igneous
Basalt
Basalt (Mafic Extrusive)
igneous
Quartz Vein in Gneiss or Basalt
Milky Quartz (SiO2) within Metamorphic Host Rock
Metamorphic or Igneous with Mineral Inclusion
Slickenside
Tectonic Fault Scarp Surface
metamorphic
Sandstone (with Iron Staining)
Arenite (primarily SiO2 with Fe2O3/FeO(OH) oxides)
sedimentary
Sandstone or Quartzite
Arenite (if sedimentary) / Quartzite (if metamorphic)
Sedimentary or Metamorphic
Sandstone (Glacial Cobble)
Arenite / Sedimentary Rock (primarily SiO2)
sedimentary
Quartzite Cobble
Metamorphosed Quartz Sandstone (SiO2)
metamorphic
Druzy Quartz on Matrix
Silicon Dioxide (SiO2)
mineral
Vesicular Basalt with Quartz/Chalcedony
Vesicular Basalt (primarily Plagioclase, Pyroxene, and Olivine with SiO2 infill)
igneous