Tree Agate
Silicon Dioxide (SiO2) with Chlorite inclusions
sedimentary
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.
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Concrete fragment with Aggregate
Anthropogenic Concrete with Calcarious and Siliceous Aggregate
sedimentary (anthropogenic/man-made)
Fossil Coral
Hexagonaria (Rugose coral) / Rugosa
fossil
Light-colored weathered stone, possibly limestone or quartz-rich rock
Indeterminate; likely calcitic limestone (mostly CaCO₃) or quartz sandstone (SiO₂)
sedimentary
Chert (Jasper/Flint variety)
Silicon Dioxide (SiO2)
sedimentary
Iron-stained quartz-rich rock, possibly jasper or chert
Microcrystalline quartz (SiO₂) with iron oxides/hydroxides
mineral
Unidentifiable Specimen
Undetermined
Unknown
Concrete
Anthropogenic Conglomerate
sedimentary
Septarian Nodule
Septarian Concretion (CaCO3-rich mudstone with Calcite/Aragonite veins)
sedimentary
Ocean Jasper
Silicon Dioxide (SiO2)
Mineral_variety_of_Chalcedony
Druzy Quartz (on Chalcedony/Agate base)
Silicon Dioxide (SiO2)
mineral
Blue Chalcedony
Silicon Dioxide (SiO2) - Microcrystalline Quartz
mineral
Chert (Flint) River Pebble
Microcrystalline Quartz (SiO2)
sedimentary
Quartz (River Pebble)
Quartz (SiO₂ - Silicon Dioxide)
Mineral
Limestone (specifically Fossiliferous Limestone)
Calcium Carbonate (CaCO3)
sedimentary
Quartz
Silicon Dioxide (SiO₂)
Mineral
Limestone (specifically Carboniferous Limestone)
Calcium Carbonate (CaCO3)
sedimentary
Basalt
Basalt (Mafic volcanic rock)
igneous
Clear Quartz Crystal
Quartz (Silicon Dioxide - SiO2)
mineral
Quartz Druzy
Silicon Dioxide (SiO2)
mineral
Fossiliferous Limestone (Chert/Clay mixed)
Calcium Carbonate (CaCO3) / Silicon Dioxide (SiO2)
sedimentary
Unidentifiable Rock Fragment
Uncertain
Amethyst cluster
Amethyst, purple quartz (SiO₂)
mineral
Agate Geode with Quartz
Silicon Dioxide (SiO2)
mineral
Quartz Nodule / Agate Geode
Silicon Dioxide (SiO2)
sedimentary
Milky Quartz
Quartz (Silica / Silicon Dioxide), SiO2
mineral
Ironstone / Limonite Concretion
Hydrated Iron Oxide Rock (FeO(OH)·nH2O with SiO2)
sedimentary
Quartz (Druzy on Matrix)
Silicon Dioxide (SiO2)
mineral
Agate Geode
Silicon Dioxide (SiO2) - Banded Chalcedony with Quartz
mineral
Geode / Fossilized Gastropod or Shell Cast
Silicon dioxide (Quartz) replacement / fossil mold
sedimentary
Siltstone/Sandstone (possibly Wonderstone or Picture Sandstone)
Clastic Sedimentary Rock (primarily SiO2 with Iron Oxide inclusions)
Sedimentary
Clear Quartz
Silicon Dioxide (SiO2)
mineral
Quartz Druzy
Crystalline Silicon Dioxide (SiO2)
mineral
Quartz (Druzy)
Silicon Dioxide (SiO2)
mineral
Picture Jasper
Silicon Dioxide (SiO2) with iron oxide inclusions
sedimentary
Quartz Pebble
Silicon Dioxide (SiO2)
sedimentary
Quartz (Agate/Chalcedony variety)
Silicon Dioxide (SiO2)
mineral
Quartz-rich chalcedony (likely silicified rock)
Microcrystalline quartz, SiO₂; possibly silicified limestone or jasper
mineral
Basalt
Basalt
igneous
Chert Concretion with Iron Oxide Staining
Microcrystalline Quartz (SiO2)
sedimentary
Chert (Yellow Jasper)
Microcrystalline Quartz (SiO2)
sedimentary
Iron-rich brown stone, possibly weathered chert or ironstone
Undetermined; likely iron-oxide-bearing silica-rich rock (chert/ironstone)
sedimentary