Unidentifiable Rock Fragment
Uncertain
Category
Sedimentary Rock (Technically A Microcrystalline Quartz Mineral Aggregate)
Browse sedimentary rock (technically a microcrystalline quartz mineral aggregate) specimens identified by the Rock Identifier community.
River Rocks (Basalt and Sedimentary Stones)
Mafic Igneous Rock (Basalt) and Clastic Sedimentary Rock
igneous and sedimentary
Quartz Druzy Geode Fragment
Silicon Dioxide (SiO2)
mineral
Sandstone
Arenite (SiO2 based with mineral cement)
sedimentary
Sandstone (River Cobble)
Clastic sedimentary rock (primarily SiO2 with various lithic fragments)
sedimentary
Red Jasper
Silicon Dioxide with Hematite impurities (SiO2 + Fe2O3)
mineral
Picture Jasper
Silicon Dioxide (SiO2) with iron oxide and clay inclusions
sedimentary
Banded Gneiss
Gneiss (Metamorphic Rock)
metamorphic
Chert (Flint) with Glauconite
Microcrystalline Quartz (SiO2)
sedimentary
Red Quartzite (Ferruginous Quartz)
Quartzite (SiO2 with Fe2O3 inclusions)
metamorphic
Satin Spar Gypsum
Calcium Sulfate Dihydrate (CaSO4·2H2O)
Mineral
Limestone with Calcite Veins
Sedimentary Calcium Carbonate (CaCO3)
sedimentary
Sandstone (Weathered Pebble)
Arenite (SiO2 primarily)
sedimentary
Basalt
Vesicular Basalt
igneous
Sandstone (Quartzose)
Arenite (primarily SiO2)
sedimentary
Sandstone (with biological crust)
Arenite (SiO2 based)
sedimentary
Mexican Crazy Lace Agate
Silicon Dioxide (SiO2) with iron and aluminum inclusions
mineral
Amygdaloidal Basalt
Amygdaloidal Basalt (extrusive volcanic rock)
Igneous
Chert (specifically Jasper/Carnelian Agate)
Microcrystalline Quartz (SiO2)
sedimentary
Sandstone (Quartzose Sandstone)
Arenite (SiO2 principal component)
sedimentary
Piddock bored rock (likely Mudstone or Shale)
Ichnofossil (Gastrochaenolites borings) in Fine-grained Sedimentary Rock
sedimentary
Conglomerate
Conglomerate (Detrital sedimentary rock)
sedimentary
Quartzite
Quartzite (primarily composed of SiO O₂)
Sedimentary Rock
Chert or Flint (polished/water-worn)
Chert (a microcrystalline or cryptocrystalline variety of quartz, SiO2). Flint is a specific variety of chert.
Sedimentary (most likely, as Chert is a sedimentary rock often found as nodules in limestone or as bedded deposits; however, it can also form by metasomatic replacement, which leans towards metamorphic processes under certain conditions)
Conglomerate
Clastic sedimentary rock (Puddingstone)
sedimentary
Chalcedony (Agate/Quartz pebble)
Silicon dioxide (SiO2) - Microcrystalline Quartz
mineral
Granite
Granite (Felsic Plutonic Rock)
igneous
Banded Agate (specifically Carnelian Agate slice)
Chalcedony (cryptocrystalline variety of Quartz), SiO2
mineral
Sandstone (Ferruginous)
Arenite (primarily SiO2 with iron oxide cement)
sedimentary
Granite Pebble
Granite (a plutonic igneous rock composed primarily of quartz, feldspar, and mica/amphibole)
igneous
Carnelian
Carnelian (Silicon Dioxide, SiO2)
mineral
Sandstone
Arenite (composed primarily of SiO2)
sedimentary
Sandstone (Quartzose)
Sandstone (clastic sedimentary rock, primarily SiO2)
sedimentary
Fossiliferous Chert (with Brachiopod or Mollusk fragments)
Silicon dioxide (SiO2) with Calcium Carbonate (CaCO3) inclusions
sedimentary
Sandstone (Red)
Arenite (SiO2 with Fe2O3)
sedimentary
Glacial Cobble (likely Granitic or Gneissic)
Granite/Gneiss Glacial Erratic
igneous
Gneiss
Gneiss (High-grade Metamorphic Rock)
metamorphic
Clear Quartz
Silicon Dioxide (SiO2)
mineral
Septarian Nodule (Dragon Stone)
Septarian concretion (composition: CaCO3 - Calcite, Aragonite, and Siderite/Limestone)
sedimentary
Jasper
Silicon dioxide / Chalcedony (SiO2)
Sedimentary
Ferruginous Sandstone
Sandstone (rich in iron oxides/hydroxides)
sedimentary
Geode (Chert or Quartz Nodule)
Silicon Dioxide (SiO2)
sedimentary