Quartzite (Pink/Red variety)
Quartzite (SiO2 with iron oxide impurities)
metamorphic
Category
Sedimentary Rock (Specifically A Clastic Sedimentary Rock Formed Into A Cobble)
Browse sedimentary rock (specifically a clastic sedimentary rock formed into a cobble) specimens identified by the Rock Identifier community.
Quartzite (River Cobble)
Quartzite (SiO2)
metamorphic
Serpentinite (often containing Jadeite/Nephrite)
Antigorite-rich Serpentine Rock, (Mg, Fe)3Si2O5(OH)4
metamorphic
Basalt with Iron Oxidation
Mafic Igneous Rock (primarily Plagioclase and Pyroxene)
igneous
Pyrite and Sunstone
Iron Sulfide (FeS2) and Plagioclase Feldspar ((Ca,Na)Al(Al,Si)Si2O8)
mineral
Quartz-veined Mudstone or Argillite
SiO2 (Quartz) in Siltstone/Mudstone matrix
sedimentary
Pink Granite with Quartz Vein
Phaneritic Plutonic Felsic Rock (K-feldspar + Quartz + Plagioclase + Mica)
igneous
Quartzite
Quartzite (primarily SiO2)
metamorphic
Sandstone Chert/Quartzite
Silicon Dioxide (SiO2) - Sedimentary Sandstone / Orthoquartzite
sedimentary
Chert (or Flint)
Chert (microcrystalline or cryptocrystalline quartz, SiO2)
Sedimentary
Quartz on Matrix
Silicon Dioxide (SiO2)
mineral
Unidentified Rock Fragment
Unknown
Rock
Pink Granite
Phaneritic Felsic Igneous Rock (Granite)
igneous
Amethyst Lace Agate / Banded Amethyst
Silicon Dioxide (SiO2) with Fe3+ impurities
mineral
Blue Chalcedony (likely dyed Agate)
Silicon Dioxide (SiO₂)
mineral
River Pebbles (Stream-rounded rocks)
Fluvial Detritus (varied mineralogy)
Mixed (predominantly sedimentary and igneous)
Basalt with Epidote (Porphyry)
Basalt (with inclusions of Epidote/Feldspar)
igneous
Ethiopian Fire Opal
Hydrated Silica (SiO2·nH2O)
mineral
White Marble
Recrystallized Calcite (CaCO3)
metamorphic
Chert (and Jasper/Flint variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Basalt Pebble
Basalt (Extrusive Mafic Igneous)
igneous
Orange Quartzite / Carnelian Agate
Silicon Dioxide (SiO2)
metamorphic
Granitoid (Granite/Diorite)
Course-grained Plutonic Igneous Rock
igneous
Concretion or Geode (unbroken)
Varied (depending on mineral composition and cementing agent). For quartz-lined geodes, the scientific name of the dominant mineral would be Quartz (SiO2). For calcite-lined geodes, Calcite (CaCO3). Concretions are often composed of cryptocrystalline quartz (chert), calcite, or iron oxides.
Sedimentary rock (specifically a concretion or possibly a geode)
Yellow Chert or Jasper
Microcrystalline Quartz (SiO2)
sedimentary
Quartz (likely) or a Quartzite Pebble
Silicon dioxide (SiO2) for quartz. If it's quartzite, it's a metamorphic rock primarily composed of quartz.
Mineral, specifically a detrital grain
Inspirational River Stone (Quartzite)
Metamorphosed Quartz-rich Rock (Quartzite) with SiO2 composition
metamorphic
Quartz Geode
Silicon Dioxide (SiO2)
mineral
Granite
Phaneritic Felsic Igneous Rock (Granite)
igneous
Moss Agate
Silicon Dioxide (SiO2) with inclusions
mineral
Quartzite
Quartzite (SiO2)
metamorphic
Yellow Chert (Jasper)
Chalcedony (SiO2) with iron oxide inclusions
sedimentary
River Pebble (Quartz/Jasper)
Silicon Dioxide (SiO2)
sedimentary
Vesicular Basalt with Amygdaloidal Infill
Basalt (Mafic Extrusive Igneous Rock)
igneous
Fire Opal (Common/Precious in Matrix)
Hydrated Silica (SiO2·nH2O)
mineral
Chert (Chert Nodule with Chalky Cortex)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
sedimentary
Limonite (Iron Ore)
Goethite and related iron hydroxides (FeO(OH)·nH2O)
mineral
Chert / Flint
Chert (Cryptocrystalline Silica, SiO2)
sedimentary
Chert (Field Stone/Pebble)
Microcrystalline or cryptocrystalline Quartz (SiO2)
sedimentary
Chert (Iron-Stained)
Microcrystalline Silica (SiO2)
sedimentary
Brachiopod Fossil in Shale
Phylum Brachiopoda (often species of Order Spiriferida or Rhynchonellida)
sedimentary
Quartz Druzy on Agate (River Cobble)
Silicon Dioxide (SiO2)
Mineral / Sedimentary (often associated with volcanic hosts)