Chert (Flint)
Microcrystalline Quartz (SiO2)
Category
Browse organic (non rock) specimens identified by the Rock Identifier community.
Chert (Flint)
Microcrystalline Quartz (SiO2)
Conglomerate
Conglomerate (clastic sedimentary rock)
Rounded dark river pebble, likely basalt
Basalt; fine-grained mafic volcanic rock, typically plagioclase + pyroxene ± olivine
Limestone
Calcareous sedimentary rock (CaCO3)
Fossilized Coral (Petrified Coral)
Lithostrotionella (example genus) / Scleractinia
Orange Quartzite (River Pebble)
Quartzite (SiO2 with iron oxide inclusions)
Quartzite Cobble
Quartzite (primarily SiO2)
Fossilized Bivalve Shell
Class Bivalvia (fossilized)
Polished petrified wood
Silicified wood, primarily microcrystalline quartz (SiO₂) replacing organic tissue
Green Slate or Metamorphic Rock with Moss/Lichen
Metamorphic rock / Phyllite or Slate variant
Obsidian
Volcanic glass
Quartzite
Quartzite (SiO2)
Banded Chert
Silicon Dioxide (SiO2)
Obsidian
Obsidian (principally SiO2 + MgO, Fe3O4)
Chert (Jasper variation)
Silicon Dioxide (SiO2)
Quartzite
Metamorphic Quartzite (predominantly SiO2)
Quartzite Cobble
Quartzite (SiO2)
Quartzite
Metamorphic Rock (Quartzite), primarily SiO2
Quartzite with inclusions
Metamorphosed Quartz-rich Rock (SiO2)
Quartzite Pebble (River Rock)
Quartzite (mainly SiO2)
Quartzite (Engineered Stone)
Silicon Dioxide (SiO2) based synthetic composite
Slate
Slate (Metamorphic Rock)
Chert (Flint)
Chert (SiO2)
Chert (Flint)
Chert (̑SiO2)
Chert (Black Flint)
Silicon Dioxide (SiO2)
Chert (Pebble)
Chert (Microcrystalline Quartz, SiO2)
Chert (Jasper)
Microcrystalline Quartz (SiO2)
Chert (Flint)
Silicon Dioxide (SiO2)
Banded Chert with Quartz Veining
Microcrystalline Quartz (SiO2)
Gray Quartzite River Rock
Meta-quartzite (SiO2)
Red Quartzite
Quartzite (primarily SiO2)
Mahogany Obsidian
Volcanic Glass (predominantly SiO2 with Fe2O3 inclusions)
Gold Ore (in Quartz/Sulfide matrix)
Native Gold (Au) in Quartz (SiO2) and Pyrite (FeS2)
Basalt
Basalt
Dyed or treated turquoise-like tumbled stone
Likely turquoise (CuAl₆(PO₄)₄(OH)₈·4H₂O), though blue-green magnesite or howlite imitation is possible
Quartzite
Quartzite (primarily SiO2)
Limestone (Weathered/Silicified)
Sedimentary carbonate rock (primarily CaCO3)
Weathered sandstone cobble
Quartz-rich sandstone, primarily SiO₂ with clay/iron-oxide cement
Petrified Wood
Silicified wood (SiO2)
Chert
Microcrystalline Quartz (SiO2)
Ironstone Concretion (Ironstone Gourd)
Limonite/Goethite Concretion (FeOO(H))
Quartzite
Quartzite (Metamorphic rock composed primarily of quartz)