Orange Quartzite / River Pebble
Quartzite (primarily SiO2)
metamorphic
Category
Man Made Object (Coin)
Browse man made object (coin) specimens identified by the Rock Identifier community.
Green Slate (Greenstone)
Metamorphic shale (varied composition)
metamorphic
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
mineral
Gneiss
Gneiss (a metamorphic rock)
Metamorphic
Gneiss
Gneiss (High-grade regional metamorphic rock)
metamorphic
Basalt with Quartz Veins
Basalt (composition: SiO2, MgO, FeO, Al2O3, CaO)
igneous
Ironstone Concretion (Iron-rich Mudstone)
Siderite / Geothite concretion (FeCO3 / FeO(OH))
sedimentary
Tektite (Indochinite)
Tektite (High-silica natural glass)
mineraloid / impact glass
Gneiss (with Quartz and Mica)
Gneiss
metamorphic
Moqui Marble (Shaman Stone)
Iron Oxide Concretion (composed primarily of Quartz sand with Hematite/Goethite shell)
sedimentary
Ferruginous Sandstone (with possible trace fossils)
Arenite with Iron-Oxide Cement (SiO2 with Fe2O3)
sedimentary
Bi-Color Tourmaline (or Watermelon Tourmaline)
Tourmaline (complex borosilicate mineral group with general formula AD3G6(BO3)3T6O18(OH,O)4)
Mineral
Fossil Coral (Favosites Honeycomb)
Favosites (Genus), Phylum Cnidaria, Class Anthozoa
sedimentary
Granite (Thin Section)
Granite (Felsic Plutonic Rock)
igneous
Granite
Phaneritic Plutonic Felsic Rock (Granite)
igneous
Limonite (Iron Ore/Hydrated Iron Oxide)
Limonite (mixture of FeO(OH)·nH₂O minerals, mainly Goethite, FeO(OH) and Lepidocrocite, FeO(OH))
Mineral
Chalcedony Geode
Chalcedony (SiO2) within a geode structure
Mineral Geode/Sedimentary or Volcanic related
Fluorite
Fluorite (Calcium Fluoride, CaF2)
Mineral
Banded Gneiss (with possible weathered sulfide or iron staining)
Gneiss, potentially with iron oxide/hydroxide staining (e.g., limonite) or weathered sulfides
Metamorphic
Phyllite
Phyllite
metamorphic
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Milky Quartz
Quartz (Silicon Dioxide - SiO2)
mineral
Pumice
Pumice (extrusive volcanic rock)
igneous
Quartzite
Quartzite (primarily SiO2)
metamorphic
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
mineral
Anthracite Coal
Anthracite (Carbon-rich metamorphic rock)
metamorphic
Pumice
Vesicular volcanic glass (primarily SiO2)
igneous
Basalt
Mafic volcanic rock (Basalt)
igneous
Ferruginous Quartz (Iron-stained Quartz)
Silicon Dioxide with Iron Oxide (SiO2 + Fe2O3)
mineral
Chert (Flint) Nodule
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Milky Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Sandstone Pebble
Arenite (primarily Quartz, SiO2)
sedimentary
Coquina or Fossilized Shell Aggregate
Calcareous bioclastic sedimentary rock (CaCO3)
sedimentary
Basalt (with possible quartz veinsing)
Basalt
igneous
Granite Cobble
Granite (Phaneritic Igneous Rock)
igneous
Schist
Schist (various mineralogical compositions including mica, chlorite, talc, etc.)
Metamorphic
Granite
Phaneritic plutonic rock (composed of Quartz, Feldspar, and Mica/Amphibole)
igneous
Sunstone
Plagioclase Feldspar (specifically Oligoclase variety containing hematite or goethite inclusions)", composition: (Ca,Na)(Al,Si)2Si2O8
Mineral
Granite
Granite (Felsic intrusive igneous rock)
igneous
Coquina
Coquina (Bioclastic Limestone)
sedimentary
Quartzite
Quartzite (primarily SiO2)
metamorphic
Chrysocolla Chalcedony
Hydrated Copper Phyllosilicate (Cu,Al)2H2Si2O5(OH)4 + SiO2
mineral