Quartz Geode
Silicon Dioxide (SiO2)
sedimentary
Category
Rock
Browse rock specimens identified by the Rock Identifier community.
Banded Slate or Siltstone with Quartz/Calcite Veins
Protolith-derived Siltstone or Slate (varies based on degree of metamorphism)
metamorphic
Dalmation Jasper (or Dalmation Stone)
Dalmation Stone (composed of Perthite, Quartz, and Arfvedsonite)
igneous
Granodiorite
Phaneritic-textured Intrusive Granodiorite
igneous
River Pebble (Gravel)
Clastic sedimentary rock (likely Siltstone or Mudstone pebble; SiO2 with various impurities)
sedimentary
Diorite
Diorite (Intermediate intrusive igneous rock)
igneous
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Banded Slate
Slate (Metamorphosed Siltstone/Mudstone)
metamorphic
Moonstone
Orthoclase (Potassium Aluminum Silicate), Formula: (K,Na)AlSi3O8
mineral
Quartz Vein Rock
Quartz (Silicon Dioxide, SiO2)
igneous
Chalcedony (Agate/Chert variety)
Silicon Dioxide (SiO2)
mineral
Serpentinite (often called Jade or Nephrite substitute)
Serpentinite (composed primarily of Antigorite, Lizardite, or Chrysotile)
metamorphic
Quartz (Smoky/Granular variety)
Silicon Dioxide (SiO2)
mineral
Sandstone (Micaceous)
Clastic Sedimentary Rock (primarily SiO2 with Mica)
sedimentary
Quartz-veined Mudstone or Argillite
SiO2 (Quartz) in Siltstone/Mudstone matrix
sedimentary
Basalt with Quartz/Quartzite Veins
Aphanitic Mafic Volcanic Rock with Siliceous Infillings
igneous
Red sandstone
Ferruginous quartz arenite (iron-oxide–cemented sandstone)
sedimentary
Granite
Granite (Felsic Plutonic Rock)
igneous
Likely weathered basalt or andesite fragment
Fine-grained volcanic rock, likely basaltic-andesite; exact identification requires testing
igneous
Basalt
Extrusive Igneous Rock
igneous
Basalt Pebble
Extrusive Igneous Rock
igneous
Shale
Clastic Sedimentary Rock
sedimentary
Rounded gray stone, likely basalt or andesite
Fine-grained mafic to intermediate volcanic rock; likely basalt (plagioclase ± pyroxene, possibly olivine)
igneous
Basalt
Basalt (Mafic volcanic rock)
igneous
Sandstone
Clastic sedimentary rock (primarily SiO2)
sedimentary
Basalt with Granite Inclusions (Xenoliths)
Mafic igneous rock (Basalt) with Sialic minerals
igneous
River Pebble (Quartzite or Chert)
Silicon Dioxide (SiO2)
metamorphic or sedimentary
Basalt
Basalt (Aphanitic-fine grained mafic igneous rock)
igneous
Banded gneiss pebble
Gneiss, commonly quartz–feldspar–mica gneiss
metamorphic
Granite
Phaneritic Igneous Rock (Granite)
igneous
Dark-colored Igneous Rock (likely Basalt or Diabase)
Basalt (extrusive igneous) or Diabase (intrusive igneous)
Igneous Rock
Unknown Rock Specimen
igneous
Granite
Granite
igneous
Andesite Porphyry
Andesite Porphyry
Igneous
Shale or Slate with Quartz Veins
Shale (fine-grained clastic sedimentary rock) or Slate (low-grade metamorphic rock formed from shale) with Quartz (SiO2) veins
Metamorphic, likely Sedimentary with Quartz veins
Conglomerate
Conglomerate rock
sedimentary
Conglomerate
Conglomerate rock
sedimentary
Conglomerate
Conglomerate rock
sedimentary
Sandstone or Limestone
Sedimentary Rock
Sedimentary
Sedimentary Rock with Crafts (Pet Rock)
Sedimentary rock decorated with synthetic materials
sedimentary
Sandstone
Arenite
sedimentary
Rounded quartz-rich pebble
Lithic pebble; likely quartz/quartzite with iron-oxide staining
sedimentary