Botryoidal Chalcedony (Agate)
Cryptocrystalline Quartz (SiO2)
mineral
Category
Sedimentary Or Igneous (Secondary Formation)
Browse sedimentary or igneous (secondary formation) specimens identified by the Rock Identifier community.
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K2 Jasper (K2 Granite)
Azurite in Granite (Biotite Granite containing Azurite)
igneous
Pyrite
Iron Pyrite (FeS2)
mineral
Dark metamorphic rock, likely biotite schist or gneiss
Quartz–feldspar–biotite metamorphic rock; exact identification requires a fresh surface and testing
metamorphic
Gneiss (Gneissic Granite Pebble)
Metamorphic rock rich in Quartz, Feldspar, and Mica
metamorphic
Weathered, quartz-rich metamorphic rock (likely schist or gneiss)
Quartz–feldspar–mica schist/gneiss, with surface lichens and iron-oxide staining
metamorphic
Honey Calcite
Calcium Carbonate (CaCO3)
mineral
Orange Calcite
Calcium Carbonate (CaCO3)
mineral
Orange Calcite
Calcium Carbonate (CaCO3)
mineral
Blue Calcite
Calcium Carbonate (CaCO3)
mineral
Blue Calcite
Calcium Carbonate (CaCO3)
mineral
Chalcedony (Moonstone variant or White Agate)
Silicon Dioxide (SiO₂)
mineral
Chalcedony (Agate/Carnelian variant)
Silicon Dioxide (SiO2)
mineral
Quartz Geode Fragment
Silicon Dioxide (SiO2)
mineral
Chert / Flint (with quartz or calcite inclusion)
Silicon dioxide (SiO2)
sedimentary
Carnelian Agate
Chalcedony (SiO2) with iron oxide inclusions
mineral
Banded Chert / Agate
Silicon Dioxide (SiO2)
sedimentary
Limonite (Iron-rich Siltstone / Sandstone base)
Hydrous ferric oxide mixture (FeO(OH)·nH2O)
sedimentary
Grey Banded Agate
Silicon Dioxide (SiO2)
sedimentary
Quartz (Citrine / Yellow Quartz)
Silicon Dioxide (SiO2)
mineral
Quartz-veined Metamorphic Pebble
Silicate-rich metamorphic rock with quartz veins (SiO2)
metamorphic
Firewood (Wood Log)
Lignum (Plant tissue composed of cellulose and lignin)
Organic (Non-geological)
Okenite
Okenite, Ca3Si6O15·6H2O
mineral
Blue Calcite
Calcium Carbonate (CaCO3)
mineral
Gold Nugget
Native Gold (Au)
mineral
Basalt with Amygdule
Aphanitic Mafic Volcanic Rock (Basalt) with Zeolite/Quartz Infill
igneous
Banded Gneiss / Metamorphic River Pebble
Gneiss (Foliated Metamorphic Rock)
metamorphic
Gneiss
Gneiss
metamorphic
Ironstone Matrix with Jasper / Chert
Ferruginous Chert / Limonitic Jasper (SiO2 with Fe-oxides)
sedimentary
Red Jasper
SiO2 (Silicon Dioxide) with Fe2O3 (Hematite)
sedimentary
Basalt with Quartz Veining
Basalt (Mafic Extrusive Igneous Rock) with SiO2 (Silicon Dioxide) veins
igneous
Quartz (Citrine or Iron-Stained variety)
Silicon Dioxide (SiO2)
mineral
Green Calcite
Calcium Carbonate (CaCO3)
mineral
Green Jasper
Microcrystalline Quartz (Chalcedony), SiO2
sedimentary
Fluorite
Calcium fluoride (CaF2)
mineral
Satin Spar (Selenite)
Gypsum (CaSO4·2H2O)
mineral
Chert (with Quartz Vein)
Chert (Siliceous sedimentary rock, predominantly Microcrystalline Quartz SiO2)
sedimentary
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Rounded river pebble
Indeterminate lithic clast; likely weathered sandstone or quartz-rich sedimentary rock
sedimentary
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
mineral
Banded Gneiss Pebble
Gneiss (Metamorphic Rock)
metamorphic