Diamond
C (Carbon)
gemstone
Category
Sedimentary (Alluvial Deposit)
Browse sedimentary (alluvial deposit) specimens identified by the Rock Identifier community.
Learn about Sedimentary (Alluvial Deposit) in the encyclopedia
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Milky Quartz
Silicon Dioxide (SiO2)
mineral
Fairburn Agate
Silicon Dioxide (SiO2) - Chalcedony / Cryptocrystalline Quartz
sedimentary
Conglomerate
Conglomerate (clastic sedimentary rock)
sedimentary
Conglomerate
Conglomerate (clastic sedimentary rock)
sedimentary
Rounded brown-gray stone, possibly weathered conglomerate or sandstone
Indeterminate clastic sedimentary rock; likely poorly cemented sandstone/conglomerate
sedimentary
Chert (Siliceous Pebble)
Microcrystalline / Cryptocrystalline Quartz (SiO2)
sedimentary
Quartzite pebble
Quartzite
metamorphic
Quartz (Peach/Pink Variety)
Silicon Dioxide (SiO2)
mineral
Conglomerate
Conglomerative Rudite (SiO2/CaCO3 matrix)
sedimentary
Honey-yellow chalcedony (likely common opal or silicified material)
Microcrystalline quartz, SiO₂; possibly hydrated silica opal, SiO₂·nH₂O
mineral
Quartz crystal (likely milky or cloudy quartz)
Quartz, silicon dioxide (SiO₂)
mineral
Weathered conglomerate pebble
Polymictic conglomerate, likely quartz- and feldspar-rich clasts in a cemented matrix
sedimentary
Weathered polymictic gravel/conglomeratic rock
Polymictic conglomerate or poorly lithified alluvial gravel; chiefly quartz, feldspar, mica, and dark lithic fragments
sedimentary
Petrified Wood
Silicified Wood (SiO2 - Silicon Dioxide)
sedimentary
Polished jasper/chalcedony nodule
Microcrystalline quartz (SiO₂), likely jaspery chalcedony with iron-oxide staining
mineral
Rough Sapphire (Corundum)
Corundum (Al2O3)
mineral
Gold Nugget
Native Gold (Au)
mineral
Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Gravelly, weathered sediment (likely glacial till)
Unconsolidated diamicton; mixed lithologies, commonly including quartz, feldspar, and weathered silicate rock fragments
sedimentary
Red Jasper
Silicon Dioxide (SiO2) with Iron Oxide inclusions
sedimentary
Weathered quartz-rich rock, likely arkose or quartzite
Quartz-dominant siliciclastic rock; probable arkose (quartz + feldspar), possibly weakly metamorphosed quartzite
sedimentary
Conglomerate
Clastic Sedimentary Conglomerate (SiO2, CaCO3, etc.)
sedimentary
Conglomerate
Conglomerate (lithified rudite)
sedimentary
Conglomerate (Quartz Pebble Conglomerate)
Quartz Pebble Conglomerate
sedimentary
Conglomerate
Conglomerate (clastic sedimentary rock)
sedimentary
Conglomerate
Conglomerate (clastic sedimentary rock)
sedimentary
Conglomerate with iron-rich concretions
Polymictic conglomerate; concretions likely goethite/limonite-rich ironstone
sedimentary
Exposed Aggregate Concrete (Pea Gravel)
Concrete with Siliceous Alluvial Gravels
sedimentary (man-made conglomerate)
Conglomerate (with Jasper pebble)
Conglomerate / Microcrystalline Quartz (Jasper)
sedimentary
Rough Agate/Chert Nodules
Cryptocrystalline Quartz (SiO2)
sedimentary
Quartz-rich breccia or conglomerate
Siliciclastic breccia/conglomerate, likely containing quartz and iron-oxide-stained rock fragments
sedimentary
Poppy Jasper
Jasper (variety of Chalcedony), SiO2 (Silicon Dioxide)
sedimentary
Jasper
Microcrystalline Quartz (SiO2)
sedimentary
Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Conglomerate
Quartz Conglomerate
sedimentary
Banded River Cobble (Argillite or Shale)
Laminated Mudstone / Argillite
sedimentary
Raw quartz crystal
Quartz (silicon dioxide, SiO₂), likely milky or iron-stained quartz
mineral
Conglomerate
Conglomerate rock
sedimentary
Rounded polymictic conglomerate (pebble)
Clast-supported conglomerate; mainly quartz- and feldspar-bearing lithic clasts in a sandy matrix
sedimentary
Agate
Silicon Dioxide / Cryptocrystalline Quartz (SiO2)
mineral
River gravel and cobbles
Mixed alluvial clasts, likely including granite, basalt, quartzite, and sandstone
sedimentary