Sandstone (likely Arkosic or Lithic Sandstone)
Arenite (SiO2 based with mineral inclusions)
Category
Browse organic materia (not a rock or mineral) specimens identified by the Rock Identifier community.
Sandstone (likely Arkosic or Lithic Sandstone)
Arenite (SiO2 based with mineral inclusions)
Granite
Granite (Felsic Plutonic Rock)
Amygdaloidal Basalt
Amygdaloidal Basalt (with secondary mineral infilling)
Note regarding baguette production (not a rock)
Digital text image - Somali language
Sandstone (likely Quartzose Sandstone)
Arenite (SiO2 based)
Chert (Jasper/Flint variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Quartz Crystal (specifically a Double-Terminated variety)
Silicon Dioxide (SiO2) - Low Quartz
Shatter Cone
Impactite (Shatter Cone texture)
Sandstone
Arenite (primarily SiO2)
Sandstone
Sandstone (arenite is a more specific geological term for a clean sandstone, while wacke refers to a dirty sandstone with significant matrix)
Milky Quartz
Silicon Dioxide (SiO2)
Quartz-veined Basalt
Amygdaloidal or Porphyritic Basalt with Silicon Dioxide (SiO2) vein
Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
Amethyst
Silicon Dioxide (SiO2) with iron impurities
Shell Cameo (Sardonyx Shell)
Cassis madagascariensis (Sardonyx shell)
Calcite (Yellow/Orange variety - sometimes called Honey Calcite)
Calcite
Granite
Granite (a plutonic rock)
Biotite Schist
Biotite Schist (Rich in K(Mg,Fe)3AlSi3O10(OH)2)
Sandstone
Clastic sedimentary rock (primarily SiO2)
Quartz Vein in Host Rock
Silicon Dioxide (SiO2) within a metamorphic matrix
Jasper (Iron-stained Chert)
Silicon Dioxide (SiO2) with impurities of Hematite or Goethite
Sandstone (Quartzose)
Arenite (primarily SiO2)
Chert / Flint
Chert (varietal name for microcrystalline quartz). Chemical formula: SiO₂
Quartz Geode Fragment
Silicon Dioxide (SiO2)
Bicolor Quartz Pebble
Silicon Dioxide (SiO2) with mineral inclusions
Chert (specifically Flint or Gray Chert)
Silicon Dioxide (Microcrystalline Quartz), SiO2
Limonite (Iron Ore)
Limonite (Hydrous iron(III) oxide-hydroxide mixture, primarily FeO(OH)·nH2O)
River Rock (likely Siltstone or fine-grained Sandstone)
Clastic Sedimentary Rock
Quartz Pebble
Silicon Dioxide (SiO2)
Sandstone (with Lichen)
Arenite (primarily SiO2)
Note regarding image quality
Quartz (Rock Crystal) with minor impurities
Quartz (SiO2)
Gold-Bearing Quartz
Silicon Dioxide with Native Gold (SiO2 + Au)
Quartz (River Pebble)
Silicon Dioxide (SiO2)
Chert (often called Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Quartz in Basalt (Xenocryst)
Silicon Dioxide (SiO2) in Mafic Igneous Volcanic Rock
Amethyst
Amethyst (Silicon Dioxide, SiO2)
Quartz Vein in Schist
Quartz (SiO2) in Mica Schist
Petrified Wood
Silicified Wood (SiO2 - Silicon Dioxide)
Sandstone
Arenite (SiO2 primarily)
Basalt with Quartz Veining
Basalt (Mafic Extrusive Igneous Rock) with SiO2 (Silicon Dioxide) veins
Quartz-Veined Mudstone
Argillaceous Mudstone with Quartz Veining