Green Opal
Hydrated amorphous silica (SiO2·nH2O)
mineral
Category
Organic (Non Rock)
Browse organic (non rock) specimens identified by the Rock Identifier community.
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Quartzite Cobble
Meta-quartzite
metamorphic
Fossilized Bone
Permineralized Vertebrate Bone
fossil
Limestone Pebble
Sedimentary carbonate rock (CaCO3)
sedimentary
Banded Limestone
Calcareous sedimentary rock (CaCO3)
sedimentary
Quartzite with Iron Inclusions
Metamorphosed Quartz-rich Rock (SiO2)
metamorphic
Limestone or Sandstone Cobble
Sedimentary rock (Calcium carbonate or Quartz based)
sedimentary
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Limestone
Calcareous sedimentary rock (CaCO3)
sedimentary
Sandstone Pebble
Arenite (SiO2 based)
sedimentary
Bauxite
Bauxite (Al2O3·2H2O mixed with iron oxides)
sedimentary
Granite
Granite (Plutonic Igneous Rock)
igneous
Quartzite
Metamorphic Rock (Mainly SiO2)
metamorphic
Granite
Granite (Felsic Plutonic Rock)
igneous
Fossiliferous Limestone with Rugose Coral
Calcite (CaCO3) matrix containing Rugosa (order of extinct solitary and colonial corals)
sedimentary
Quartzite
Quartzite (SiO2)
metamorphic
Yellow Quartzite Pebble
Quartzite (SiO2)
metamorphic
Quartzite River Rock
Quartzite (SiO2)
metamorphic
Granodiorite
Granodiorite (intermediate plutonic rock)
igneous
Quartzite
Quartzite (SiO2-rich metamorphic rock)
metamorphic
Quartzite River Rock
Metamorphic Rock (Recrystallized Quartz - SiO2)
metamorphic
River Stone (Quartzite)
Metamorphic Quartzite (primarily SiO2)
metamorphic
Quartzite
Quartzite (SiO2-rich metamorphic rock)
metamorphic
Quartzite
Quartzite (composed primarily of Silica, SiO2)
metamorphic
Fossil Coral (Petoskey / Horn Coral Sliced Button)
Scleractinia / Rugosa (Silurian-Devonian Anthozoa)
fossil
River Pebble (Granite/Sandstone Pebble)
Rounded Quartz/Feldspar Gravel Clast
igneous
Quartzite
Quartzite (SiO2)
metamorphic
Poppy Jasper
Microcrystalline Quartz (SiO2) with mineral inclusions
sedimentary
Quartzite River Rock
Metamorphic Quartzite (SiO2)
metamorphic
Quartzite
Quartzite (primarily SiO2)
metamorphic
Quartzite Pebble
Metamorphic Quartzite (primarily SiO2)
metamorphic
Snowflake Obsidian
Spherulitic Obsidian (Amorphous Volcanic Glass with Cristobalite inclusions)
igneous
Black Obsidian
Obsidian (Volcanic Glass), primarily SiO2 (Silicon Dioxide)
igneous
Fossiliferous Sandstone
Sedimentary rock containing invertebrate fossils
fossil
Fossilized Bark
Lepidodendron / Sigillaria fossil impression
fossil
Conglomerate
Conglomerate (clastic sedimentary rock)
sedimentary
Sandstone
Sandstone (Quartz-rich Arenite / SiO2)
sedimentary
Quartzite
Quartzite (mostly SiO2)
metamorphic
Quartzite Pebble
Quartzite
metamorphic
Black Obsidian
Volcanic Glass (felsic)
igneous
Chert (Common Opal or Agate)
Microcrystalline Quartz (SiO2)
sedimentary
Sandstone Pebble
Arenite (primarily SiO2)
sedimentary