Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Category
Browse not a rock (man made origin) specimens identified by the Rock Identifier community.
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Sandstone (Banded)
Clastic Sedimentary Rock: Arenite
Granite
Phaneritic Felsic Igneous Rock
Granite
Granite (Felsic Plutonic Rock)
Basalt
Basalt (principally Plagioclase and Pyroxene)
Basalt
Basalt (composition predominately plagioclase feldspar and pyroxene)
Chert (Jasper variation)
Silicon Dioxide (SiO2)
Granite
Granite (Felsic Plutonic Rock)
Quartzite
Quartzite (primarily SiO2)
Amygdaloidal Basalt with Epidote
Vesicular Basalt with secondary Epidote/Quartz mineral infill
Quartz Vein in Host Rock
Silicon Dioxide (SiO2) within Metasedimentary or Igneous matrix
Quartz (Druzy)
Silicon Dioxide (SiO2)
Quartz Vein in Sedimentary Rock
Silicon Dioxide (SiO2) with host Chert or Limestone
Ocean Jasper
Orbicular Jasper (Silicon Dioxide with impurities), SiO2
Milky Quartz
Silicon Dioxide (SiO2)
Conglomerate
Conglomerate (SiO2, Al2O3, Fe2O3, CaCo3)
Chert / Flint
Chert (Cryptocrystalline Silica, SiO2)
Quartz (Milky/Yellowish variety)
Silicon Dioxide (SiO2)
Chert (Jasper)
Microcrystalline Quartz (SiO2) with iron oxide impurities
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Fossiliferous Limestone
Biogenic Limestone (Calcium Carbonate, CaCO3)
Concretion
Septarian concretion (likely containing Calcite or Siderite)
Chert Breccia
Brecciated Microcrystalline Quartz (SiO2)
Dyed Agate
Silicon Dioxide (SiO2)
Chert (Field Stone/Pebble)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Brachiopod Fossil in Shale
Phylum Brachiopoda (often species of Order Spiriferida or Rhynchonellida)
Jasper (Chert)
Silicon Dioxide (SiO2)
Amygdaloidal Basalt
Amygdaloidal Basalt (Mafic Extrusive volcanic rock)
Milky Quartz
Silicon Dioxide (SiO2)
Limonite (Iron Ore)
Goethite and related iron hydroxides (FeO(OH)·nH2O)
Basalt Porphyry
Porphyritic Basalt
Sandstone
Arenite (predominantly Quartz Sandstone)
Sandstone (Pebble/Cobble)
Sandstone (arenite is a more precise term for sandstone with less than 15% matrix; this specimen appears to be a lithic or quartz arenite)
Quartz Geode
Silicon Dioxide (SiO2)
Granite
Granite (composed primarily of Quartz, Alkali Feldspar, and Plagioclase)
Red Quartzite / Metasandstone River Pebble
Quartzite (primarily SiO2 with hematite inclusions)
Sandstone
Arenite (composed primarily of SiO2)
Sandstone (Ferruginous)
Arenite (Fe2O3 enriched)
Granite Gneiss
Felsic Gneiss
Sunstone
Oligoclase or Andesine (Labradorite) Feldspar (Na,Ca)(Si,Al)4O8
Serpentinite (Serpentine Rock)
Primarily composed of serpentine group minerals, such as antigorite, chrysotile, and lizardite. Chemical formula for serpentine minerals is (Mg,Fe)3Si2O5(OH)4.
Agate
Silicon dioxide (SiO2)