Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Category
Sedimentary (Alluvial Deposit)
Browse sedimentary (alluvial deposit) specimens identified by the Rock Identifier community.
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Diamond
C (Carbon)
gemstone
Conglomerate
Clastic Sedimentary Rock (Conglomerate)
sedimentary
Conglomerate
Conglomerate (clastic sedimentary rock)
sedimentary
Yellow Quartzite Pebble
Quartzite (SiO2)
metamorphic
Tumbled milky quartz pebble
Quartz (silicon dioxide, SiO₂)
mineral
Small clear crystal, probably quartz
Quartz (SiO₂), possibly a tiny quartz chip or translucent feldspar fragment
mineral
Iron-Stained Quartz (Riverside Cobble)
Silicon Dioxide (SiO2) with Limonite/Hematite inclusions
mineral
Conglomerate (possibly concrete-like natural breccia)
Lithified, poorly sorted clastic rock with angular to subrounded mineral and rock fragments in a finer matrix
sedimentary
Conglomerate
Conglomerate (Clastic sedimentary rock)
sedimentary
Yellow Quartzite (or Quartz River Pebble)
Silicon Dioxide (SiO2)
metamorphic
Jasper pebble (possibly Red Jasper or Lake Superior Agate/Jasper mix)
Silicon Dioxide (SiO2) with Hematite inclusions
sedimentary
Conglomerate
Conglomerate (clastic sedimentary rock)
sedimentary
Tumbled quartz-rich chalcedony (likely carnelian or orange jasper)
Microcrystalline quartz, SiO₂, colored mainly by iron oxides
mineral
Gold Nugget Jewelry
Native Gold (Au)
mineral
Conglomerate
Conglomerate (clastic sedimentary rock)
sedimentary
Chalcedony (Agate / Chert)
Silicon Dioxide (SiO2)
mineral
Agate (River Pea)
Microcrystalline Chalcedony (SiO2)
sedimentary
Conglomerate
Conglomerate (clastic sedimentary rock)
sedimentary
Conglomerate
Polymictic clast-supported conglomerate
sedimentary
Ruby (faceted)
Corundum (Al2O3 with chromium traces)
gemstone
Tumbled yellow chalcedony (likely citrine or yellow jasper)
Microcrystalline quartz, SiO₂; exact identification requires testing
mineral
Polymictic conglomerate
Clast-supported conglomerate, typically quartz- and feldspar-rich in a dark matrix
sedimentary
Conglomeratic aggregate / pebble-rich concrete-like rock
Polymictic conglomerate (likely glacial or beach-derived gravel matrix); exact identification uncertain from image
sedimentary
Chert (and Quartz Gravel)
Chert (Cryptocrystalline Quartz, SiO2)
sedimentary
Polished carnelian cabochon
Carnelian, a red-orange chalcedony (microcrystalline quartz), SiO₂
gemstone
Ruby
Corundum (Al2O3:Cr)
mineral
Red jasper (likely polished/tumbled)
Jasper, an opaque microcrystalline variety of quartz (SiO₂), colored mainly by iron oxides
mineral
Sandstone
Arenite
sedimentary
Conglomerate
Conglomerate (clastic sedimentary rock)
sedimentary
Quartz-rich conglomeratic breccia
Polymictic clast-supported conglomerate/breccia, dominated by quartz and feldspar
sedimentary
Conglomerate (possibly breccia)
Polymictic clastic conglomerate; rounded clasts in a dark, likely volcanic-lithic matrix
sedimentary
Red Jasper
Silicon Dioxide (SiO2) with Iron Oxide inclusions
mineral
Chalcedony Pebble / Rough Agate
Silicon Dioxide (SiO2)
mineral
Conglomerate
Conglomerate (clastic sedimentary rock)
sedimentary
Tumbled milky quartz pebble
Quartz, silicon dioxide (SiO₂), microcrystalline to coarsely crystalline variety
mineral
Rounded yellow-brown chert or jasper pebble
Microcrystalline quartz (SiO₂), likely iron-stained chert/jasper
sedimentary
Rounded sandstone pebble
Lithified quartz-rich sandstone, likely arkosic or feldspathic sandstone
sedimentary
Limonite-stained Chert
Microcrystalline Quartz (SiO2) with Hydrated Iron Oxides (FeO(OH)·nH2O)
sedimentary
Hessonite Garnet (Grossular)
Ca3Al2(SiO4)3 (Grossular Garnet)
gemstone
Blue Sapphire
Corundum (Al2O3 with trace amounts of Fe and Ti)
gemstone
Quartzite pebble
Quartzite
metamorphic