Gravel and Sediment Sample
Mixed clastic sediment
sedimentary
Category
Sedimentary (Alluvial Deposit)
Browse sedimentary (alluvial deposit) specimens identified by the Rock Identifier community.
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Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Basalt with Caliche Crust
Aphanitic Mafic Igneous Rock with Calcium Carbonate (CaCO3) coating
igneous
Quartz Pebble
Silicon Dioxide (SiO2)
sedimentary
Quartz Pebble
Silicon dioxide (SiO2)
sedimentary
Chalcedony-rich jasper (orbicular/pisolithic jasper)
Microcrystalline quartz (SiO₂), commonly with iron-oxide pigments and possible quartz pseudospheres
sedimentary
Yellow Quartz (Citrine/Yellow Jasper Pebble)
Silicon Dioxide (SiO2)
sedimentary
Cassiterite in Iron-rich Matrix
Cassiterite (SnO2)
mineral
Nephrite Jade
Ca2(Mg, Fe)5Si8O22(OH)2
metamorphic
Mixed rounded gravel and weathered rock fragments
Polymictic alluvial or glacial gravel; composition appears to include basaltic, quartz-rich, and feldspathic clasts
sedimentary
Conglomeratic gravel / polymictic breccia
Polymictic rudite, likely anthropogenic or beach/stream gravel; composition varies
sedimentary
Quartz (Chalcedony / Rough Quartz Pebble)
Silicon Dioxide (SiO2)
mineral
Conglomerate
Sedimentary Conglomerate
sedimentary
River Pebble
Weathered Sedimentary Rock Fragment
sedimentary
Conglomerate
Sedimentary Conglomerate
sedimentary
Quartz Pebble
Silicon Dioxide (SiO2)
sedimentary
Quartz Pebbles
Silicon Dioxide (SiO2)
sedimentary
Quartz Pebble
Silicon Dioxide (SiO2)
sedimentary
River Pebble (Quartz/Chert mix)
Silicon Dioxide (SiO2) with various inclusions
sedimentary
Quartz Pebble
Silicon Dioxide (SiO2)
sedimentary
Chert Pebble
Microcrystalline silica (SiO2)
sedimentary
Rounded river pebble
Likely lithic sandstone or weathered quartz-rich rock; exact identification requires testing
sedimentary
Yellow Sapphire (Corundum)
Corundum (Aluminum Oxide, Al2O3)
mineral
Quartz (Milky or Smoky)
Silicon Dioxide (SiO2)
mineral
Quartzite Pebble
Quartzite (primarily SiO2)
metamorphic
Quartz (Smoky/Milky variant)
Silicon Dioxide (SiO2)
mineral
Quartz / Quartzite Fragment
Silicon Dioxide (SiO2)
mineral / metamorphic
Milky Quartz with Iron Staining
Silicon Dioxide (SiO2)
mineral
Quartz pebble
Silicon dioxide (SiO2)
sedimentary
Mixed Rock and Mineral Collection
Various geological specimens
igneous, sedimentary, and metamorphic
Fairburn Agate
Cryptocrystalline Quartz (SiO2) with inclusions
sedimentary
Jasper Pebble
Microcrystalline Quartz (SiO2)
sedimentary
River Pebble
Weathered Rock Fragment
sedimentary
River-rounded landscaping pebbles
Mixed alluvial gravel; commonly quartzite, granite, basalt, sandstone, and quartz
sedimentary
Sapphire
Corundum (Al2O3)
mineral
Conglomerate
Clastic Sedimentary Rock (Conglomerate)
sedimentary
River Pebble (Gravel)
Rounded clastic sediment
sedimentary
Quartz Pebble
Silicon Dioxide (SiO2)
sedimentary
Jasper (Brown Jasper)
Microcrystalline Quartz (Chalcedony), SiO2
sedimentary
Alluvial stream gravel (mixed rock specimens)
Polymictic fluvial deposit; likely mixtures of quartzite, sandstone, shale, chert, basalt, and granite-derived minerals
sedimentary
Quartz (Smoky/Milky variety)
Silicon Dioxide (SiO2)
mineral
Quartz (Iron-Stained)
Silicon Dioxide (SiO2)
mineral