Quartz pebble with iron stains
Macrocrystalline Quartz (SiO2)
Category
Browse sedimentary like (industrial composite) specimens identified by the Rock Identifier community.
Quartz pebble with iron stains
Macrocrystalline Quartz (SiO2)
Quartz vein in metamorphic rock
Crystalline Silicon Dioxide (SiO2) in Host Rock
Milky Quartz Mushroom Carving
Quartz (Silicon Dioxide, SiO2)
Anthracite Coal
Anthracite (Carbon-based organic sedimentary rock transitioned to metamorphic)
Diamond
Natural Diamond (Carbon, C)
Ferruginous Sandstone (Ironstone)
Iron-rich Arenite
Chlorite (Small Flakes/Sand)
Chlorite Group (Magnesium Iron Aluminum Silicate Hydroxide - (Mg,Fe)3(Si,Al)4O10(OH)2·(Mg,Fe)3(OH)6)
Quartzite
Quartzite (primarily SiO2)
Rough Diamond
Diamond (pure carbon / C)
Blue slag glass or dyed glass-like industrial material
Amorphous silicate glass; likely copper-bearing blue slag, but possibly colored man-made glass
Desert Rose
Gypsum or Barite (CaSO4·2H2O or BaSO4)
Ruby in Zoisite
Anyolite (composite of Corundum [Al2O3] and Zoisite [Ca2Al3(SiO4)(Si2O7)O(OH)])
Black Tourmaline (Schorl)
Schorl (NaFe3Al6(BO3)3Si6O18(OH)4)
Granite Pegmatite with Tourmaline and Muscovite
Pegmatite (Feldspar: KAlSi3O8, Quartz: SiO2, Schorl: NaFe2+3Al6(Si6O18)(BO3)3(OH)3(OH))
Schist
Mica Schist
Quartzite
Quartzite (SiO2)
Banded Agate (Tumbled)
Silicon Dioxide (SiO2)
Garnet-bearing Schist / Conglomerate Specimen
Metamorphic rock with almandine garnet porphyroblasts
Rough Diamond
Natural Diamond (Carbon, C)
Agate Slices and Clear Quartz Points
Agate (SiO2 Chalcedony) and Clear Quartz (SiO2 Crystalline)
Fluorite (likely Green Fluorite variant)
Calcium Fluoride (CaF2)
Limestone
Calcium Carbonate (CaCO3)
Sandstone (Weathered Pebble)
Arenite (SiO2 primarily)
Pumice
Pumice (volcanic glass formed of highly vesicular rough textured rock)
Limestone
Sedimentary Calcium Carbonate (CaCO3)
Ironstone (Limonitic Concretion)
Limonite (FeO(OH)·nH2O) with Goethite and Hematite inclusions
Quartz (Milky/Smoky variety on matrix)
Silicon Dioxide (SiO2)
Vesicular Basalt
Basalt (Mafic volcanic rock)
Agate
Silicon dioxide (Chalcedony), SiO2
Agate
Silicon Dioxide (Chalcedony), SiO2
Quartz Pebble
Silicon Dioxide (SiO2)
Agate
Silicon Dioxide (Chalcedony), SiO2
Magnetite / Ironstone Pebble
Magnetite (Fe3O4)
Chalcedony Geode Fragment
Silicon Dioxide (SiO2)
Slag Glass
Amorphous Silica / Glass Slag
Fossilized shell or brachiopod
Likely a calcareous brachiopod or bivalve fossil; exact identification requires clearer detail and scale
Ironstone
Ferruginous Sedimentary Rock (composed of Goethite, Hematite, and Limonite)
Slag Glass
Vitreous Silicate Residue
Smoky Quartz
Silicon Dioxide (SiO2)
Basalt
Basalt (Mafic volcanic rock)
Basalt (Vesicular)
Basalt
Quartzite
Quartzite (SiO2)