Carnelian
Carnelian (a variety of Chalcedony); SiO2 (Silicon Dioxide)
Category
Browse mineral like byproduct (often mistaken for igneous rock or meteorite) specimens identified by the Rock Identifier community.
Carnelian
Carnelian (a variety of Chalcedony); SiO2 (Silicon Dioxide)
Sandstone (with Iron concretions/staining)
Arenite (composed primarily of Quartz and Feldspar with Iron Oxide cement)
Metaconglomerate
Metaconglomerate (Quartzite conglomerate)
Granite
Phaneritic Plutonic Felsic Rock (KAlSi3O8 - SiO2 - NaAlSi3O8)
Sandstone
Arenite (SiO2 based)
Vesicular Basalt (Scoria)
Vesicular Basalt
Sandstone (Picture Sandstone)
Arenite (primarily SiO2)
Sandstone (clastic)
Clastic Sedimentary Rock (primarily composed of SiO2)
Clear Quartz Cluster
Silicon Dioxide (SiO2)
Basalt
Basalt
Milky Quartz in Conglomerate Matrix
Silicon Dioxide (SiO2) within Clastic Sedimentary Rock
Amethyst
Amethyst (Silicon Dioxide, SiO2)
Rough Sapphire
Corundum (Al2O3)
Sandstone
Clastic Sedimentary Rock (composed primarily of Quartz: SiO2)
Hematite
Iron(III) oxide (Fe2O3)
Milky Quartz
Silicon Dioxide (SiO2)
Sandstone (Ferruginous)
Arenite (SiO2 with iron oxide impurities)
Chalcedony (Moonstone variant or White Agate)
Silicon Dioxide (SiO₂)
Red Sandstone
Arenite
Basalt (with possible weathering or secondary mineral crust)
Basalt (Aphanitic Mafic Igneous Rock)
Granitic Gneiss
Gneiss (Polymetamorphic Granitic Gneiss)
Pyrite
Iron Sulfide (FeS2)
Schist
Mica Schist (Variable chemistry, often rich in muscovite and biotite)
Porphyry
Porphyritic Rock
Smoky Quartz and Biotite Schist
Quartz-Biotite Schist (SiO2 + K(Mg,Fe)3AlSi3O10(F,OH)2)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Sunstone
Oligoclase (Plagioclase Feldspar) - (Ca,Na)(Al,Si)4O8
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Rainbow Fluorite
Fluorite (Calcium Fluoride, CaF2)
River Pebble (Likely Chert or Fine-Grained Sandstone/Quartzite)
Siliciclastic clast (likely Chert or Quartzarenite/Quartzite pebble)
Sandstone (Quartzose)
Arenite (composed mainly of SiO2)
Sandstone (likely Fossiliferous)
Arenite / Sedimentum arenaceum
Chert (Siliceous Mudstone variant)
Microcrystalline quartz (SiO2)
Biotite Schist
Biotite Schist (K(Mg,Fe)3AlSi3O10(OH,F)2)
Rose Quartz
Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese
Basalt
Mafic volcanic rock (primarily plagioclase feldspar and pyroxene)
Thunderegg (Agate-filled Geode Node)
Silicon dioxide (SiO2) with various inclusions
Milky Quartz
Silicon Dioxide (SiO2)
Quartz Geode Fragment
Silicon Dioxide (SiO2)
Ammonite Fossil
Ammonoidea (subclass)
Chert (Brown variety / Common Jasper)
Microcrystalline Quartz (SiO2)
Sandstone
Arenite (composed primarily of SiO2)