Red Sandstone (Iron-rich)
Ferruginous Sandstone (variable formula, primarily SiO2 + Fe2O3)
sedimentary
Category
Sedimentary Rock (Altered)
Browse sedimentary rock (altered) specimens identified by the Rock Identifier community.
Red Jasper (Brecciated or Mottled)
Silicon Dioxide (SiO2) with iron oxide inclusions
sedimentary
Black Veined Jasper (Spiderweb Jasper)
Silicon Dioxide (SiO2)
sedimentary
Ferruginous Sandstone (Ironstone)
Arenite with Iron-Oxide Cement (FeO(OH)·nH2O / Fe2O3)
sedimentary
Sandstone (with Iron Oxide)
Arenite with Limonite/Hematite staining
sedimentary
Chert (Flint variety)
Chert (SiO2)
sedimentary
Honeycomb Coral Fossil
Favosites (extinct genus of tabulate coral)
sedimentary
Gneiss
Foliated Metamorphic Rock (Gneiss)
metamorphic
Clear Quartz
Silicon Dioxide (SiO2) / Rock Crystal
mineral
Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
mineral
Quartzite with Chert inclusions
Metamorphosed Quartz-rich Rock (SiO2)
metamorphic
Gneiss (specifically a Banded Gneiss cobble)
Gneiss (composed mainly of Quartz, Feldspar, and Biotite/Amphibole)
metamorphic
Chert (Limestone-based)
Silicon Dioxide (SiO2)
sedimentary
Biotite Schist
Biotite-rich Schist (K(Mg,Fe)3AlSi3O10(OH,F)2)
metamorphic
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
mineral
Gneiss (specifically Pink Gneiss)
Gneiss (high-grade regional metamorphic rock)
metamorphic
Red Jasper
Jasper (SiO2) with Hematite (Fe2O3) inclusions
sedimentary (microcrystalline quartz)
River Stone (Chert/Siltstone)
Cryptocrystalline Quartz (SiO2) with trace impurities
sedimentary
Poppy Jasper
Jasper (variety of Chalcedony), SiO2 (Silicon Dioxide)
sedimentary
Red Sandstone
Arenite (with Iron Oxide cement)
sedimentary
Chert Nodule (with Ironstone Cortex)
Microcrystalline Silica (SiO2)
sedimentary
Chert (Septarian Concretion/Nodule)
Microcrystalline silica (SiO2) with carbonate mineral veining
sedimentary
Yellow Jasper
Silicon Dioxide (SiO2) - Opaque Chalcedony
sedimentary
Wishing Stone (Quartz-veined Siltstone or Graywacke)
Hydrothermal Quartz vein in matrix of SiO2 (Quartz) and Al2O3 (Clay minerals)
sedimentary
Chert (Jasper/Flint variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Moss Agate
Agate (Silicon Dioxide, SiO2) with dendritic inclusions
sedimentary
Red Sandstone
Arenite (with Iron Oxide)
sedimentary
Chert (Flint variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Red Chert (Jasper)
Silicon Dioxide (SiO2)
sedimentary
Banded Sandstone (Liesegang Rings)
Sedimentary sandstone with Iron oxide precipitates
sedimentary
Chert (with Quartz veins)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (Iron-stained)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Quartz (Milky/Clear Quartz)
Silicon Dioxide (SiO2)
mineral
Dalmatian Jasper (or Dalmatian Stone)
Dalmatian Stone (A peralkaline felsite composed of feldspar, quartz, and sodic amphibole)
igneous
White Opal (Common)
Hydrated Silica (SiO2·nH2O)
mineral
Fluorite (likely Green Fluorite variant)
Calcium Fluoride (CaF2)
mineral
Quartz / Quartzite
Silicon Dioxide (SiO2)
metamorphic
Banded Chert (River Pebble)
Microcrystalline Quartz (SiO2)
sedimentary
Goniatite Fossil
Goniatitida (Order), fossilized in limestone/calcite (CaCO3)
sedimentary
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Septarian Nodule Segment (Commonly known as Dragon Stone or Lightning Stone)
Septarian Nodule (CaCO3 / Hydrated Calcium Carbonate)
sedimentary
Fossilized Coral (Petoskey Stone type)
Hexagonaria percarinata (Fossilized Rugose Coral)
sedimentary