Chert (often called Flint when dark)
Sedimentary cryptocrystalline quartz (SiO2)
Category
Browse igneous or sedimentary (water worn) specimens identified by the Rock Identifier community.
Chert (often called Flint when dark)
Sedimentary cryptocrystalline quartz (SiO2)
Chert (Flint)
Silicon Dioxide (SiO2) - Cryptocrystalline Quartz
Jasper with Quartz Veining
Silicon Dioxide (SiO2) with iron oxide inclusions
Yellow Quartz (Chalcedony)
Silicon Dioxide (SiO2)
Granite River Pebble
Granite (composed of Quartz, Feldspar, and Biotite)
Basalt Pebble
Basalt
Basalt
Basalt (composition of plagioclase, pyroxene, and olivine)
Basalt
Basalt
Basalt with Vesicular Texture
Basalt (SiO2 range 45-52%)
Conglomerate
Conglomeratic Sandstone / Polymictic Conglomerate
Chert (often called Flint for dark variants)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Jasper (likely river-worn)
Silicon Dioxide (SiO2)
Jasper in Quartz (River Cobble)
Silicon Dioxide (SiO2) with Ferric Iron inclusions
Jasper (Green Jasper/Heliotropic Chert)
Silicon Dioxide (SiO₂)
White Quartz Pebble
Silicon Dioxide (SiO2)
Basalt Pebble
Basalt (Mafic Volcanic Rock)
Granite Pebble
Granite (Phaneritic intrusive igneous rock)
Pink Granite
Phaneritic Felsic Intrusive Igneous Rock
Basalt
Basalt (Mafic Extrusive)
Basalt
Basalt
Quartz (Milky/Yellowish)
Silicon Dioxide (SiO2)
Conglomerate
Conglomerate (clastic sedimentary rock)
Dendritic Jasper (River Stone)
Silicon Dioxide (SiO2) with Manganese/Iron Oxide inclusions
Quartz Pebble
Silicon Dioxide (SiO2)
Granite
Felsic Plutonic Rock (primarily SiO2)
Milky Quartz with Mineral Inclusions
Silicon Dioxide (SiO2)
Jasper (Banded Argillite/Chert mix)
Silicon Dioxide (SiO2) with iron oxide inclusions
Quartz Pebble
Silicon Dioxide (SiO2)
Basalt (tumbled/water-worn)
Extrusive mafic igneous rock
Gneiss (specifically a granitic gneiss cobble)
Gneiss (high-grade regional metamorphic rock)
Granite Cobble
Granite (Phaneritic Quartz-Feldspar Felsic Rock)
Yellow Jasper
Silicon Dioxide (SiO2) with iron oxide impurities
Milky Quartz (Water-worn Pebble)
Quartz (Silicon Dioxide) - SiO2
Chert (Jasper/Flint variety)
Microcrystalline Quartz (SiO2)
River Cobbles (Basalt, Quartzite, and Sandstone mix)
Fluvial detritus (primarily SiO2, Plagioclase, and Pyroxene mix)
Yellow Jasper
Silicon Dioxide (SiO2) with hydrated iron oxide impurities (Goethite)
Chert (Jasper/Common Chert Pebble)
Microcrystalline Quartz (SiO2)
Conglomerate
Conglomerative Rudite (SiO2/CaCO3 matrix)
Jasper with Quartz inclusion
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Fossil Coral (likely Favosites or Honeycomb Coral)
Class Anthozoa, Order Tabulata, Genus Favosites
Quartz pebble
Silicon Dioxide (SiO2)
Quartz Pebble
Silicon Dioxide (SiO2)