Gabbro (River Cobble)
Gabbro (mafic intrusive rock)
igneous
Category
Igneous Or Sedimentary (Water Worn)
Browse igneous or sedimentary (water worn) specimens identified by the Rock Identifier community.
Learn about Igneous Or Sedimentary (Water Worn) in the encyclopedia
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Banded Chert
Silicon Dioxide (SiO2)
sedimentary
Pebble
Lithic fragment / Water-worn rock
sedimentary
Jasper
Silicon Dioxide (Microcrystalline Quartz, SiO2)
sedimentary
Milky Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Sandstone and River Pebbles
Sedimentary Rock (Sandstone / Quartzite / Chert)
sedimentary
Granite Water-Worn Pebble
Intermediate to Felsic Phaneritic Igneous Rock
igneous
Jasper
Microcrystalline Quartz (SiO2)
sedimentary
Conglomerate
Conglomerate (Sedimentary rock)
sedimentary
Milky Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Quartz Pebble (with probable Iron staining)
Silicon Dioxide (SiO2)
mineral
Banded Basalt / Lave Stone or Gneiss Pebble
Igneous/Metamorphic banded pebble
igneous
Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Wishing Stone (Graywacke with Quartz Vein)
Graywacke Sandstone containing a Quartz (SiO2) intrusion
sedimentary
Banded Agate
Silicon Dioxide (SiO2) - Microcrystalline Quartz
sedimentary
Sandstone (likely Quartzose Sandstone)
Arenite (composed primarily of SiO2)
sedimentary
Jasper or Red Quartzite
SiO2 (Silicon Dioxide with iron oxide impurities)
sedimentary or metamorphic
Riverstone Jasper
Silicon Dioxide (SiO2) with iron/clay inclusions
sedimentary
Banded Chert
Microcrystalline Quartz (SiO2)
sedimentary
Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
mineral
Greenstone / Graywacke
Metagraywacke (Chlorite-grade schistose rock)
metamorphic
River Pebble
Weathered Sedimentary Rock Fragment
sedimentary
Sandstone
Arenite (Siliclastic sedimentary rock)
sedimentary
River Pebble (likely Quartzite or Chert)
Sedimentary Clast (Silicon Dioxide dominant)
sedimentary
Gneiss (specifically a water-worn pebble)
Gneiss
metamorphic
Milky Quartz in Epidote Host Rock
Crystalline Silicon Dioxide (SiO2) with Epidote Ca2(Al,Fe)3(SiO4)3(OH)
mineral
Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Yellow Quartz Pebble (Citrine or Iron-Stained Quartz)
Silicon Dioxide (SiO2)
mineral
Sandstone (Gneissic or Banded)
Clastic Sedimentary Rock (composed predominantly of SiO2)
sedimentary
Jasper
Silicon dioxide (SiO2)
sedimentary
Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Basalt Pebble
Extrusive Igneous Rock
igneous
Milky Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Basalt Puddle Stone
Basalt (Mafic volcanic rock)
igneous
Jasper with Quartz Vein
Microcrystalline quartz (SiO2) with impurities
sedimentary
Gneiss (Gneissic Granite Pebble)
Metamorphic rock rich in Quartz, Feldspar, and Mica
metamorphic
River Rock (Glacial Cobbles)
Fluvial Alluvium (Mixed lithology including Quartzite, Basalt, and Granite)
Mixed (predominantly sedimentary and igneous)
Jasper
Microcrystalline Quartz (SiO2)
sedimentary
Vesicular Basalt (Amygdaloidal Basalt)
Extrusive Mafic Igneous Rock
igneous
Biotite-bearing granite or granitic gneiss
Quartz–feldspar–biotite assemblage; possibly metamorphosed granite (gneiss)
igneous
Brown Pebble (Probable Chert or Siltstone)
Silicon Dioxide (SiO2) / Sedimentary Microcrystalline Quartz
sedimentary