Lignite (Brown Coal)
Humic Lignite (Carbonaceous sedimentary rock)
Category
Browse mineral within sedimentary rock specimens identified by the Rock Identifier community.
Lignite (Brown Coal)
Humic Lignite (Carbonaceous sedimentary rock)
Chert / Flint
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Pink Granite
Granite (Phaneritic Quartz-Feldspar rock)
Jasper
Silicon dioxide (SiO2)
Granite
Granite (Felsic Plutonic Rock)
Ironstone with Limonite/Goethite coating
Ferruginous Sedimentary Rock (contains Limonite FeO(OH)·nH2O)
River Pebbles (Sandstone and Quartzite)
SiO2 (Quartz) dominated clastic rocks
Jasper
Silicon Dioxide (SiO2)
Chert (Flint)
Silicon Dioxide (SiO2)
Red Jasper (Opaque Chalcedony)
Silicon Dioxide (SiO2) with Hematite (Fe2O3) inclusions
Chert (Jasper/Agate variety)
Microcrystalline Quartz (SiO2)
Ruby
Corundum (mineral species), variety: Ruby (Al2O3 with Cr3+ as the chromophore)
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Granite
Phaneritic Felsic Igneous Rock (primarily SiO2, Al2O3, K2O, Na2O)
Moqui Marble (Shaman Stone)
Iron Oxide Concretion (Hematite/Goethite shell with Sandstone core)
Jasper Agate (specifically Brecciated Jasper with Agate inclusions)
Silicon Dioxide (SiO2)
Chert / Flint
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Jade
There are two distinct minerals commonly known as Jade: Jadeite (NaAlSi2O6) and Nephrite (Ca2(Mg,Fe)5Si8O22(OH)2). Based on the appearance, these spheres are likely Nephrite.
Banded Agate (Mutton-fat or Pork-stone variety)
Silicon Dioxide (SiO2) with iron oxide inclusions
Dyed Agate Slice
Silicon Dioxide (SiO2) with artificial colorants
Red Sandstone
Arenite (with Iron Oxide / Hematite), Formula: SiO2 (Quartz) + Fe2O3 (Hematite coating)
Ironstone (with Limonite/Goethite)
Ferruginous Sedimentary Rock (contains Limonite FeO(OH)·nH2O and Hematite Fe2O3)
Quartz with Iron Stains
Quartz (SiO2) with iron oxide/hydroxide staining
Banded Gneiss (River Cobble)
Gneiss (a high-grade metamorphic rock)
Greywacke (River Pebble)
Greywacke sandstone with quartz veining
Quartzite with Quartz Veining
Quartzite (primarily SiO2)
Limonite/Goethite on Shale
Hydrous ferric oxides (FeO(OH)·nH2O) often associated with argillaceous rock
Chert (Arrowhead Fragment)
Microcrystalline Quartz (SiO2)
Ferruginous Breccia
Breccia with Iron-rich (Hematite/Goethite) Matrix
Limestone
Calcium Carbonate (CaCO3)
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Opal
Hydrous silicon dioxide (SiO2·nH2O)
Travertine (Calcareous Tufa)
Calcium Carbonate (CaCO3)
Arid Sandy Loam
Arenosols / Regosols
Granodiorite
Granodiorite (Intermediate intrusive igneous rock)
Amethyst
Silicon Dioxide with iron impurities (SiO2)
Gneiss (Metamorphic Rock)
Gneiss (high-grade regional metamorphic rock)
Chert (Flint)
Microcrystalline silica (SiO2)
Chert / Flint
Microcrystalline Quartz (SiO2)
Schist
Mica Schist
Note: Item is not a geological specimen
n/a