Milky quartz with dark host-rock inclusions
Quartz (SiO₂), likely in a granitic or metamorphic matrix
Category
Browse not a rock (synthetic material) specimens identified by the Rock Identifier community.
Milky quartz with dark host-rock inclusions
Quartz (SiO₂), likely in a granitic or metamorphic matrix
Basalt River Pebble
Basalt
Sandstone
Arenite (SiO2 composed primarily of quartz)
Chert
Silicon dioxide (SiO2)
Slag (Industrial Byproduct)
Artificial silicate/iron byproduct
Sandstone
Quartz Sandstone (predominantly)
Sandstone
Sandstone (composed predominantly of Quartz, SiO2)
River Rock
Sedimentary Rock (various compositions)
Red Sandstone
Sandstone (Quartz Arenite / Arkose with Hematite cement)
Concrete / Conglomerate (Man-made)
Artificial Conglomerate (Cementitious Composite)
Sandstone
Clastic sedimentary rock (primarily quartz arenite)
Clay Brick
Ceramic structural unit (Al2O3·2SiO2·2H2O as precursor)
Chert (Nodule)
Microcrystalline or Cryptocrystalline Silica (SiO2)
Sedimentary Sandstone
Arenite (Sedimentary Rock)
Sandstone
Arenite (primarily Quartz, SiO2)
Red Sandstone
Arenite (Ferruginous Sandstone)
Granite Cobble
Granite (Phaneritic Igneous Rock)
Sandstone
Arenite (primarily SiO2)
Sandstone
Arenite (SiO2 dominant)
Sandstone (Tumbled / Rounded)
Sedimentary Rock (Quartz arenite)
Sandstone
Arenite (SiO2 primarily)
Sandstone
Arenite (primarily Quartz-rich)
Man-made Crystal (Lead Glass)
Lead oxide-doped Silica Glass (approx. SiO2 + PbO)
Lapis Lazuli
Lapis Lazuli (a rock composed primarily of Lazurite (Na,Ca)₈[(S,Cl,SO₄,OH)₂|(Al₆Si₆O₂₄)], with varying amounts of Calcite, Pyrite, and Sodalite.)
Gravel or Crushed Stone
Fragmented Aggregate Stone
Weathered granite or granitic pegmatite cobble
Granite/granitic rock, composed mainly of quartz (SiO₂), feldspar, and minor biotite or other dark minerals; the reddish-brown areas may be iron-oxide staining or weathered accessory minerals
Mudstone
Argillite
Crushed Granite / Landscaping Gravel
Granitoid
Chert Nodules or Concretion
Cryptocrystalline Quartz (SiO2)
Petrified Wood
Silicified Wood (primarily SiO2 - Silicon Dioxide)
Limestone
Sedimentary Calcium Carbonate (CaCO3)
Sandstone
Arenite (SiO2 based)
Sandstone
Arenite (composed primarily of SiO2)
Limestone
Calcite (CaCO3)
River Stone (likely Quartzite or Limestone)
Silicon dioxide (SiO2) or Calcium carbonate (CaCO3)
Granite
Phaneritic Igneous Rock
Concrete / Anthropogenic Conglomerate
Man-made composite material (Portland cement, aggregate, and water)
Serpentine
Hydrous magnesium iron silicate, (Mg,Fe)3Si2O5(OH)4
Quartzite
Quartzite (SiO2)
Sandstone
Sandstone (SiO2 dominant)
Chert (Jasper/Agate variety)
Microcrystalline Quartz (SiO2)
Mudstone
Lutylite (group of fine-grained sedimentary rocks)