Sandstone
Arenite (composed primarily of SiO2)
sedimentary
Category
Synthetic (Not A Rock Or Mineral)
Browse synthetic (not a rock or mineral) specimens identified by the Rock Identifier community.
Limonite Concretion (Ironstone)
Limonite / Goethite (FeO(OH)·nH2O)
sedimentary
Turquoise
Hydrated phosphate of copper and aluminium (CuAl6(PO4)4(OH)8·4H2O)
mineral
Green Aventurine
Silicon dioxide (SiO2) with fuchsite inclusions
mineral
Amethyst (Geode/Druzy)
Silicon Dioxide (SiO2) with iron impurities
mineral
Granite
Granite (a plutonic igneous rock)
Igneous
Quartz / Quartzite
Silicon Dioxide (SiO2)
mineral / metamorphic
Basalt with Quartz Veins
Basalt (composition: SiO2, MgO, FeO, Al2O3, CaO)
igneous
Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
mineral
Amethyst (Chevron Amethyst)
Amethystine Quartz (SiO2)
mineral
Sandstone
Arenite (a specific type of sandstone with less than 15% matrix)
Sedimentary rock
Greenstone (Amygdaloidal Basalt)
Amygdaloidal Basalt (frequently composed of Plagioclase Feldspar, Pyroxene, and Olivine with Chlorite inclusions)
igneous
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Sandstone (with carbonaceous plant fragments)
Arenite (composed primarily of SiO2)
sedimentary
Sandstone (Ferruginous)
Arenite (SiO2 with Iron Oxide impurities)
sedimentary
Yellow Quartz (Citrine Quartz Pebble)
Silicon Dioxide (SiO2)
mineral
Carnelian
Carnelian (Silicon Dioxide - SiO2)
mineral
Quartz
Quartz (SiO2 - Silicon Dioxide)
Mineral
Rose Quartz
Silicon Dioxide (SiO2)
mineral
Red Jasper with Quartz Veining
Jasper (Silicon Dioxide, SiO2) with Quartz (SiO2) inclusions
sedimentary
Limonite (Iron Ore)
Limonite (Hydrous iron(III) oxide-hydroxide mixture, primarily FeO(OH)·nH2O)
mineral
Sandstone Cobble
Arenite (Secondary classification based on grain size)
sedimentary
Stiped Slate Beach Pebble
Low-grade Metamorphic Slate with Quartz Vein (SiO2 on Phyllosilicate base)
metamorphic
Amygdaloidal Basalt
Amygdaloidal Basalt (Mafic Volcanic Rock)
igneous
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
mineral
Sandstone
Arenite (Sedimentary rock comprising sand-sized grains)
sedimentary
Schist
Chlorite/Mica Schist
metamorphic
Gneiss
Gneiss (High-grade Regional Metamorphic Rock)
metamorphic
Vesicular Basalt
Amygdaloidal Basalt (Mafic extrusive volcanic rock)
Igneous
Gneiss
High-grade foliated metamorphic rock
metamorphic
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)
Quartz (in a rock matrix)
Quartz (SiO2)
mineral
Vesicular Basalt (Lava Rock)
Aphanitic Mafic Igneous Rock
igneous
Fuchsite on Quartz
Muscovite (KAl2(AlSi3O10)(OH)2) with Chromium impurities
metamorphic
Basalt with Olivine Phenocrysts
Porphyritic Basalt (containing Mg2SiO4 - Fe2SiO4)
igneous
Pink Granite
Phaneritic Felsic Igneous Rock (Granite)
igneous
Dendrite (Manganese Oxide Dendrites)
Psilomelane or Pyrolusite on Matrix (typically MnO2)
mineral
Dyed Dalmatian Jasper (Dalmatian Stone)
Perthitic Feldspar with Arfvedsonite inclusions
igneous
Conglomerate (River Rock Aggregate)
Conglomerate (Lithic-clast conglomerate)
sedimentary
Amethyst
Amethyst (Silicon Dioxide, SiO2)
mineral
Granite Cobble
Felsic Intrusive Igneous Rock (Granite)
igneous
Shale (sub-type: Carbonaceous Shale)
Lutaceous Sedimentary Rock
sedimentary