Foliated metamorphic cobble, likely gneiss
Biotite–quartz–feldspar gneiss (tentative)
metamorphic
Category
Sedimentary Or Igneous (Secondary Formation)
Browse sedimentary or igneous (secondary formation) specimens identified by the Rock Identifier community.
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Garnet Gneiss
Garnetiferous quartzo-feldspathic gneiss
metamorphic
Azurite Malachite
Azurite (Cu3(CO3)2(OH)2) and Malachite (Cu2CO3(OH)2)
mineral
Gold
Gold (Native Element); Au
mineral
Banded Agate
Silicon Dioxide (SiO2) - Variety of Chalcedony
sedimentary
Quartz Geode (Cracked Open Fragment)
Silicon Dioxide (SiO2)
mineral
Sandstone (Ferruginous/Banded)
Clastic Terrigenous Sandstone (SiO2 with Fe2O3 cement)
sedimentary
Hematite
Iron(III) oxide (Fe2O3)
mineral
Gold Nugget
Native Gold (Au)
mineral
Hematite (Botryoidal / Kidney Ore)
Iron Oxide (Fe2O3)
mineral
Polished Hematite Tower
Hematite (Fe2O3)
mineral
Turquoise
Turquoise - CuAl6(PO4)4(OH)8·4H2O
mineral
Botryoidal hematite (ironstone)
Hematite, Fe₂O₃; likely a botryoidal or massive iron-oxide specimen
mineral
Geode (Unopened)
Quartz/Chalcedony concretion
sedimentary
Rounded river pebble, likely basaltic or andesitic volcanic rock
Fine-grained mafic to intermediate volcanic rock; likely basalt/andesite, but exact identification requires testing
igneous
Rhodochrosite
Manganese carbonate (MnCO3)
mineral
Ferruginous Quartz (Iron-stained Quartz)
Silicon Dioxide (SiO2) with Iron Oxide (Fe2O3) inclusions
Mineral
Agate Geode
Silicon Dioxide (SiO2) - Chalcedony variety
sedimentary
Chert Nodule
Microcrystalline Quartz (SiO2)
sedimentary
Agate Geode
Silicon Dioxide (SiO2)
sedimentary
Lavender Chalcedony
Silicon Dioxide (SiO2)
mineral
Chalcedony in Limestone Host Rock
Silicon Dioxide (SiO2) within Calcium Carbonate (CaCO3)
Mineral within Sedimentary Rock
Quartz (Iron-stained)
Silicon Dioxide (SiO2)
mineral
Optical Calcite
Calcium Carbonate (CaCO3)
mineral
Agate
Silicon Dioxide (SiO2) - variety Chalcedony
mineral
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Mineral and Rock Collection (Assorted)
Mixed collection including Quartz (SiO2), Jasper (SiO2 with impurities), Rose Quartz, and Aventurine
mineral
Quartz Geode (with Calcite influence)
Silicon Dioxide (SiO2) with possible Calcium Carbonate (CaCO3)
mineral
Yellow Calcite
Calcite (Calcium Carbonate, CaCO3)
mineral
Limonite (Iron Ore)
Limonite (FeO(OH)·nH2O)
mineral
Banded Chert
Silicon Dioxide (SiO2) with impurities
sedimentary
Ferruginous Quartz
Silicon Dioxide with Iron Oxide inclusions (SiO2 + Fe2O3)
mineral
Agate
Silicon Dioxide (SiO2)
mineral
Blue Sapphire
Corundum (Al2O3)
mineral
Rough Quartz in Pegmatite Matrix
Quartz (Silicon Dioxide - SiO2) in Granitic Pegmatite
igneous
Jasper
Silicon dioxide (SiO2)
sedimentary
Weathered river cobble, possibly sandstone or volcanic tuff
Indeterminate lithology; likely fine-grained sandstone/siltstone, with possible iron-oxide veining
sedimentary
Garnet
Garnet (X3Y2(SiO4)3)
mineral
Banded Slate or Siltstone with Quartz/Calcite Veins
Protolith-derived Siltstone or Slate (varies based on degree of metamorphism)
metamorphic
Epidote
Epidote (Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH))
mineral
Chalcedony
Chalcedony (SiO2)
mineral
Gneissic Schist
Gneiss-schist (Metamorphic rock)
metamorphic