Granite Cobble
Granite (Phaneritic Quartz-Feldspar Felsic Rock)
Category
Browse igneous or sedimentary (water worn) specimens identified by the Rock Identifier community.
Granite Cobble
Granite (Phaneritic Quartz-Feldspar Felsic Rock)
Chert (Flint) Pebble
Microcrystalline Quartz (SiO2)
Jasper
Silicon dioxide (SiO2) with impurities
Sandstone (Quartzose)
Arenite (composed primarily of SiO2)
Sandstone (Ferruginous)
Arenite with Iron Oxide staining (Fe2O3)
Chert (Smooth River Pebble)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Red Jasper
Silicon Dioxide (SiO2) with iron oxide inclusions
Grey River Pebble (Likely Quartz-rich or Limestone)
Clastic Sedimentary Rock (typically SiO2 or CaCO3 based)
Jasper with Hematite Inclusions
Silicon Dioxide (SiO2) with Iron Oxide (Fe2O3)
Black Jasper
Silicon Dioxide (SiO2) with impurities
Milky Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
Greenstone (possibly Basalt or Greenschist)
Greenschist (composed primarily of chlorite, actinolite, and epidote)
White Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
Quartzite River Cobble
Quartzite (SiO2)
Jasper (brecciated or orbicular variety)
Silicon dioxide (SiO2) with iron oxide inclusions
River Cobble (likely Quartzite or Limestone)
SiO2 (Quartzite dominant) or CaCO3 (Limestone dominant)
Granodiorite Pebble
Granodiorite
Sandstone (Quartz-rich)
Sandstone (SiO2 dominated)
Jasper
Jasper (Silicon Dioxide) - SiO2
Yellow Jasper
Chalcedony (Silicon Dioxide, SiO2)
Jasper
Jasper (Silicon Dioxide, SiO2)
Favosites Fossil (Honeycomb Coral)
Favosites sp. (Extinct genus of tabulate coral)
River Jasper (Green Jasper)
Silicon Dioxide (SiO2) with impurities
Jasper
Silicon Dioxide (SiO2)
Chert (Iron-stained)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Jasper/Flint Pebble)
Microcrystalline quartz (SiO2)
Chert (River Pebble)
Chert (SiO2)
Chert Pebble
Microcrystalline Quartz (SiO2)
Sandstone (Quartz Sandstone)
Arenite (primarily SiO2)
Jasper River Pebble
Silicon Dioxide (SiO2) with iron oxide impurities
Basalt
Basalt (Mafic igneous rock)
Chert (often called Flint or River Pebble)
Chert (Microcrystalline Quartz, SiO2)
Sandstone with Liesegang Rings
Arenite with secondary Iron oxide (Limonite/Goethite) precipitation
Basalt (River Stone)
Basalt (SiO2 range 45-52%)
Basalt
Basalt (Mafic volcanic rock)
Basalt Riverstone
Basalt (Aphanitic Mafic Volcanic Rock)
Basalt River Pebble
Basalt (fine-grained mafic igneous rock)
Basalt with inclusion
Basalt (Aphanitic-Porphyritic texture)
Sodalite Syenite (popularly known as Yooperlite)
Sodalite-rich Syenite (composed of alkali feldspar and sodalite)
Diorite (Polished Cobble)
Diorite (Intermediate intrusive igneous rock)
Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Carnelian Agate (with Quartz/Chalcedony)
Silicon Dioxide (SiO2) - Microcrystalline Quartz