Biotite Mica
Biotite (K(Mg,Fe)3AlSi3O10(F,OH)2)
Category
Browse sedimentary rock (metamorphosed) specimens identified by the Rock Identifier community.
Biotite Mica
Biotite (K(Mg,Fe)3AlSi3O10(F,OH)2)
Asphalt (Bituminous Pavement Bit)
Bitumen-bound aggregate (Petrochemical-bound composite)
White Quartz
Quartz (SiO2)
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Chert Pebble (Jasper variant)
Microcrystalline Quartz (SiO2)
Rock Salt / Halite Crust
Halite (Sodium Chloride, NaCl)
Chert (or possibly Flint)
SiO2 (Silicon Dioxide)
Jasper, possibly Brecciated Jasper or Ocean Jasper due to patterns and color
Silicon Dioxide (SiO2), a variety of Chalcedony
Red Jasper
Jasper (a cryptocrystalline variety of Quartz, SiO₂)
Banded Iron Formation
Banded Iron Formation (BIF)
Quartzite
Quartzite (primarily composed of SiO O₂)
Mother of Pearl (Nacre)
Calcium Carbonate (primarily aragonite, with conchiolin)
Quartzite
Quartzite
Pink Anthracite Coal (dyed)
Anthracite Coal (Artificially Colored)
Banded Gneiss (with possible weathered sulfide or iron staining)
Gneiss, potentially with iron oxide/hydroxide staining (e.g., limonite) or weathered sulfides
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Clear Quartz (Rock Crystal Fragments)
Silicon Dioxide (SiO2)
Thunderegg (Agate-filled Geode Node)
Silicon dioxide (SiO2) with various inclusions
Banded Gneiss (River Rock/Pebble)
Gneiss (specifically a banded variety, likely a orthogneiss or paragneiss depending on parent rock)
River Rock (Quartz-dominated)
Silicon Dioxide (SiO2) mixture with varied clastic sediments
Asphalt (Road Aggregate)
Asphalt concrete / Bituminous mixture
Chert (Flint)
SiO2 (predominantly microcrystalline or cryptocrystalline quartz)
Quartz
Quartz (Silicon Dioxide - SiO2)
Dyed Quartzite
Tumbled Metamorphosed Quartz (SiO2) with artificial pigment
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2)
Sandstone
Arenite (general term for sandstone)
Quartz
Quartz (SiO₂)
Marble
Marble (primarily Calcite, CaCO3 or Dolomite, CaMg(CO3)2)
Pebble (likely Quartzite or Chert)
Clastic Sediment, potentially composed of SiO₂ (Quartz)
Quartz (likely Yellow/Orange variety, possibly Citrine or Chalcedony with iron staining)
Quartz (SiO₂)
Graphite-veined Quartzite
Meta-sedimentary Quartzite with Carbonaceous/Graphitic Inclusions (SiO2 + C)
Iron Ore / Ironstone Concretion
Mixture of iron oxide/hydroxide minerals, likely some combination of Hematite (Fe2O3), Goethite (α-FeOOH), and Limonite (a general term for hydrated iron oxides of variable composition) or potentially Bauxite (a mixture of aluminum hydroxides, often with iron oxides, (Al(OH)3) and FeO(OH)). The visual characteristics strongly suggest iron-rich material.
Red Jasper (beads)
Silicon Dioxide (SiO2) with iron inclusions
Chalk
Calcareous Ooze (composed primarily of coccoliths)
Coal (most likely Bituminous or Anthracite)
Bituminous Coal (Grade of Coal), Anthracite (Grade of Coal)
Banded Iron Formation (BIF)
Banded Iron Formation
Coal (most likely Bituminous or Anthracite)
Coal (primarily composed of carbon with varying amounts of other elements)
Cherry Creek Jasper (also known as Red Creek Jasper or Cherry Creek Agate)
Jasper, microcrystalline quartz (SiO₂)
Ocean Jasper (Orbicular Jasper)
Silicon Dioxide (SiO2)
Jasper River Pebble
Silicon Dioxide (SiO2)
Quartzite Cobble
Quartzite (SiO2)
Asphalt
Asphalt concrete (engineered material, not a naturally occurring rock/mineral in this form)