Coal (likely Bituminous or Lignite)
Organic Sedimentary Rock (Carbonaceous)
sedimentary
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.
Orange Quartzite (or Iron-Stained Quartz)
Silicon Dioxide (SiO2) with Iron Oxide impurities (Fe2O3)
metamorphic
Quartzite (Milky)
Quartzite (SiO2)
metamorphic
Granodiorite
Granodiorite (Intermediate to Felsic Intrusive Rock)
igneous
Limestone with Algal/Lichen Colonization
Calcium Carbonate (CaCO3)
sedimentary
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Massive Cryptocrystalline Quartz (Chert/Chalcedony Pebble)
Silicon Dioxide (SiO2)
sedimentary
Crushed Limestone
Sedimentary Carbonate Rock (CaCO3)
sedimentary
Mica Schist
Mica Schist (Predominantly Muscovite/Biotite)
metamorphic
Pink Granite
Granite (Felsic Plutonic Rock)
igneous
Quartz Geode
Quartz (Silicon Dioxide - SiO2) within a Chalcedony and Limonite shell
sedimentary
Jasper Breccia
Silicon Dioxide (SiO2) with impurities
sedimentary
Note: Item is not a geological specimen
Guitar Components (Steel, Nickel, Plastic, Wood)
Synthetic/Consumer Product
Note: This is a Man-Made Object (Costume/Prop Patch)
Synthetic fiber and pigments (Cellulose/Plastic-based composite)
Non-geological
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Pink Granite
Felsic Plutonic Rock (primarily Quartz, Potassium Feldspar, and Plagioclase)
igneous
Limestone
Calcareous Sedimentary Rock (CaCO3)
sedimentary
Basalt (River Pebble)
Basalt (Aphanitic Mafic Volcanic Rock)
Igneous
Basalt
Basalt (Aphanitic Mafic Igneous Rock)
igneous
Garnet Schist
Almandine-Muscovite Schist
metamorphic
Quartz Geode
Silicon Dioxide (SiO2) in Geode form
sedimentary
Limestone
Calcareous Sedimentary Rock (CaCO3)
sedimentary
Travertine
Terrestrial Sedimentary Rock (CaCO3)
sedimentary
Basalt (River Cobble)
Mafic Igneous Basalt (composed primarily of Plagioclase feldspar, Pyroxene, and Olivine)
Igneous
Chert (with Quartz vein/coating)
Microcrystalline Quartz (SiO2)
sedimentary
Unakite
Epidotized Granite
metamorphic
Picture Jasper
Silicon Dioxide (SiO2)
sedimentary
Brown Jasper
Jasper (a cryptocrystalline variety of Quartz, SiO2)
Mineral, specifically a variety of Quartz
Chert (Chert Pebble)
Microcrystalline or cryptocrystalline Quartz (SiO2)
sedimentary
Pink Granite
Granite (Alkali-feldspar granite)
igneous
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Shale
Fissile mudstone (primarily clay minerals and silt-sized quartz)
sedimentary
Sandstone (Quartz-rich)
Arenite (composed mainly of SiO2)
sedimentary
Bauxite (Laterite Clay)
Bauxite (mixture of Hydrous Aluminum Oxides: Gibbsite Al(OH)3, Boehmite and Diaspore AlO(OH))
sedimentary
Agate Geode with Quartz Druzy
Chalcedony (SiO2) and Quartz (SiO2)
mineral
Quartz Geode
Silicon Dioxide (SiO2)
mineral
Gneiss (Banded Gneiss)
Gneiss
metamorphic
Shale
Shale (comprised mostly of clay minerals and quartz)
sedimentary
Thunderegg (specifically a Jasper/Agate-filled Geode nodule)
Silicon Dioxide (SiO2) within Rhyolitic Matrix
igneous
Quartz Vein in Host Rock
Quartz (SiO2) in Mafic or Sedimentary Matrix
igneous
Quartz (River Pebble)
Silicon Dioxide (SiO2)
mineral
Orange Calcite
Calcite (Calcium Carbonate, CaCO3)
Mineral