Aragonite / Calcite Geode
Calcium Carbonate (CaCO3)
mineral
Category
Sedimentary Rock (Specifically A Concretion Or Possibly A Geode)
Browse sedimentary rock (specifically a concretion or possibly a geode) specimens identified by the Rock Identifier community.
Ironstone Concretion / Goethite Nodules
Ironstone (composed primarily of Goethite FeO(OH) and Limonite)
sedimentary
Basalt with Epidote Veins
Mafic Igneous Rock (Basalt)
igneous
Petrified Wood
Silicified Wood (SiO2)
metamorphic
Gneiss (specifically a weathered or stream-worn specimen)
Gneiss (Foliated Metamorphic Rock)
metamorphic
Quartz Geode
Silicon Dioxide (SiO2)
mineral
Gneiss (specifically Banded Gneiss)
Gneiss
metamorphic
Quartz Geode / Druzy Quartz
Silicon Dioxide (SiO2)
mineral
Ironstone (Limonitic Concretion)
Limonite (FeO(OH)·nH2O) with Goethite and Hematite inclusions
sedimentary
Sandstone with trace fossil
Sandstone, possibly with Skolithos or similar trace fossil
sedimentary
Chalcedony in Limestone Host Rock
Silicon Dioxide (SiO2) within Calcium Carbonate (CaCO3)
Mineral within Sedimentary Rock
Ironstone Concretion (Limonite/Goethite)
Goethite-rich Concretion (FeO(OH))
sedimentary
Quartz (likely Herkimer Diamond style)
Silicon Dioxide (SiO2)
mineral
Quartz Geode
Silicon Dioxide (SiO2) in a Secondary Sedimentary/Volcanic cavity
mineral
Quartz Geode (Cracked Open)
Quartz (Silicon Dioxide - SiO2)
mineral
Gneiss (specifically Micaceous Gneiss)
Gneiss (High-grade Regional Metamorphic Rock)
metamorphic
Basalt
Basalt (composition predominately plagioclase feldspar and pyroxene)
igneous
Chert (Agatized/Chalcedony variety)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (or Flint)
Chert (cryptocrystalline quartz), SiO2
Sedimentary
Septarian Nodule (Septarian Dragon Stone)
Septarian Concretion (CaCO3 + Al2Si2O5(OH)4)
sedimentary
Quartz Geode
Silicon Dioxide (SiO2)
mineral
Basalt with Vesicle/Vug
Basalt (Aphanitic Mafic Igneous Rock)
igneous
Septarian Nodule (Septarian Dragon Stone)
Septarian Concretion (Composition: Calcite, Aragonite, and Limestone/Clay)
sedimentary
Druzy Quartz on Limestone
Silicon Dioxide (SiO2)
mineral
Quartz Geode
Silicon Dioxide (SiO2) in a Geode body
sedimentary or igneous (host environment)
Red Quartz (Druzy)
Silicon Dioxide (SiO2) with Hematite inclusions
mineral
Agate Geode
Silicon Dioxide (SiO2) - variety Chalcedony/Quartz
sedimentary
Quartz (River Pebble)
Quartz (SiO₂ - Silicon Dioxide)
Mineral
Dragon Vein Agate
Silicon Dioxide (SiO2)
mineral
Agate Geode with Quartz Druzy
Chalcedony (SiO2) and Quartz (SiO2)
mineral
Geode (unopened)
Chert / Chalcedony Geode (SiO2)
sedimentary
Quartz Geode
Silicon Dioxide (SiO2)
mineral
Ironstone Concretion (Boji Stone/Moqui Marble type)
Goethite/Hematite-encrusted Sandstone Concretion
sedimentary
Vesicular Basalt (Scoria)
Extrusive Mafic Igneous Rock (primarily Plagioclase Feldspar and Pyroxene)
igneous
Agate (specifically Botswana or Lake Superior style chalcedony)
Silicon Dioxide (SiO2)
mineral
Pebble (river rock/beach pebble)
Pebble (clast size class)
Sedimentary Rock
Quartz Geode
Silicon Dioxide (SiO2) in a Secondary Formation
sedimentary
Quartz Druze on Matrix (Geode Fragment)
Quartz (Silicon Dioxide, SiO2)
mineral
Ironstone Concretion (Nutstone)
Ironstone (with High Limonite/Hematite Content)
sedimentary
Quartz Geode
Quartz (Silicon Dioxide, SiO2)
Mineral
Chert Concretion (with typical hematite/limonite staining)
Sedimentary Concretion (SiO2 with FeO(OH)⋅nH2O)
sedimentary
Celestine (or Celestite) on Matrix
Celestine (SrSO4)
mineral