Chert (and Flint)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Category
Browse sedimentary rock (technically a microcrystalline quartz mineral aggregate) specimens identified by the Rock Identifier community.
Chert (and Flint)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Chert (variously known as Flint or Jasper)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Conglomerate
Clastic sedimentary rock (Polymictic Conglomerate)
Quartz Geode
Silicon Dioxide (SiO2)
Druzy Quartz Geode (likely Smokey Quartz variety)
Silicon Dioxide (SiO2) - specifically a geode formation lined with druzy quartz crystals, with a likely brownish hue indicating smokey quartz.
River Cobble (likely Sandstone or Siltstone type)
Sandstone or Siltstone (common rock types that form river cobbles)
Quartz Geode (Nodule)
Silicon Dioxide (SiO2)
Yellow Aventurine
Quartzite with inclusions (SiO2)
Agate Geode
Silicon Dioxide (SiO2) - variety Chalcedony/Quartz
Sandstone
Arenite (composed primarily of SiO2)
Sandstone Concretion
Clastic sedimentary rock (primarily Quartz SiO2)
Sandstone (Quartzose Sandstone)
Clastic Terrigenous Sedimentary Rock (primarily SiO2)
Chert (often referred to as Flint)
Chert (Microcrystalline or cryptocrystalline Quartz, SiO2)
Quartzite
Quartzite (SiO2)
Basalt
Basalt (Mafic volcanic rock)
Puddingstone
Conglomerate (specifically a type of jasper conglomerate or quartz conglomerate)
Quartz (Gravel fragment)
Quartz (Silicon Dioxide, SiO2)
Sandstone (Banded)
Clastic Sedimentary Rock (primarily SiO2)
Asphalt (Road Aggregate)
Asphalt concrete / Bituminous mixture
Banded Calcite (Green Onyx)
Calcium Carbonate (CaCO3)
Banded Chert
Microcrystalline Quartz (SiO2)
Sandstone (Quartzose Sandstone)
Clastic Sedimentary Rock (primarily SiO2)
Granodiorite (Gneissic Pebble)
Granodiorite displaying minor foliation
Chert / Flint
Cryptocrystalline quartz (SiO2)
Satin Spar (Selenite)
Gypsum (Calcium Sulfate Dihydrate) - CaSO4·2H2O
Red Jasper with Quartz and Hematite
Silicon Dioxide (SiO2) with Ferric Iron inclusions
Quartz Vein in Host Rock
Silicon Dioxide (SiO2) within Sedimentary or Igneous Matrix
Amygdaloidal Basalt
Amygdaloidal Basalt (extrusive volcanic rock with mineral inclusions)
Obsidian
Obsidian (Volcanic Glass)
Green Banded Agate
Agate (Variety of Chalcedony/Quartz), SiO2
Coquina or Fossilized Shell Aggregate
Calcareous bioclastic sedimentary rock (CaCO3)
Sandstone (Greywacke/Siltstone variant)
Arenite / Wacke (SiO2 with diverse mineral inclusions)
Quartz Geode
Silicon Dioxide (SiO2)
Green Quartzite (Aventurine-like)
Quartzite (primarily SiO2 with chromium-rich mica or chlorite inclusions)
Flagstone (Sandstone)
Clastic Sedimentary Rock (composed of quartz and feldspar)
Banded Gneiss (River Rock/Pebble)
Gneiss (specifically a banded variety, likely a orthogneiss or paragneiss depending on parent rock)
Yellow Jasper
Silicon Dioxide (SiO2) with iron oxide impurities
Green Aventurine
Silicon Dioxide (SiO2) with Fuchsite inclusions
Jasper (likely a variety of Brecciated Jasper or a patterned variety)
Silicon dioxide (SiO2)
Dalmatian Stone
Dalmatian Jasper / Feldspathic Igneous Rock
Granite
Granite (a plutonic rock)
Quartz (Clear Quartz/Rock Crystal)
Silicon Dioxide (SiO2)