Rock Identifier

Category

Sedimentary (Alluvial Deposit)

Browse sedimentary (alluvial deposit) specimens identified by the Rock Identifier community.

Gneiss (Granitic Gneiss) (Gneiss (composed primarily of Quartz, Feldspar, and Mica/Amphibole)) — metamorphic

Gneiss (Granitic Gneiss)

Gneiss (composed primarily of Quartz, Feldspar, and Mica/Amphibole)

Chert / Yellow Jasper (Silicon Dioxide (SiO2)) — sedimentary

Chert / Yellow Jasper

Silicon Dioxide (SiO2)

Chalcedony (Blue/Grey Lace Agate) (Silicon Dioxide (SiO2)) — mineral

Chalcedony (Blue/Grey Lace Agate)

Silicon Dioxide (SiO2)

Chalcedony (Grey/White Agate) (Silicon Dioxide (SiO₂)) — mineral

Chalcedony (Grey/White Agate)

Silicon Dioxide (SiO₂)

Milky Quartz (Silicon Dioxide (SiO2)) — mineral

Milky Quartz

Silicon Dioxide (SiO2)

Chert (Agate/Flint variant) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Agate/Flint variant)

Microcrystalline Quartz (SiO2)

Red Jasper (Polished) (Silicon Dioxide (SiO2) with Hematite inclusions) — sedimentary

Red Jasper (Polished)

Silicon Dioxide (SiO2) with Hematite inclusions

Yellow Jasper (Silicon Dioxide with Iron inclusions (SiO2)) — sedimentary

Yellow Jasper

Silicon Dioxide with Iron inclusions (SiO2)

Jasper (Jasper (Silicon Dioxide, SiO2)) — sedimentary

Jasper

Jasper (Silicon Dioxide, SiO2)

Jasper (Silicon Dioxide (SiO2)) — sedimentary

Jasper

Silicon Dioxide (SiO2)

Yellow Jasper (Jasper (Silicon Dioxide, SiO2 plus various mineral impurities)) — sedimentary

Yellow Jasper

Jasper (Silicon Dioxide, SiO2 plus various mineral impurities)

Quartz Geode (Cracked Open) (Quartz (Silicon Dioxide - SiO2)) — mineral

Quartz Geode (Cracked Open)

Quartz (Silicon Dioxide - SiO2)

Blue Apatite (Apatite (Group), Ca5(PO4)3(F,Cl,OH)) — mineral

Blue Apatite

Apatite (Group), Ca5(PO4)3(F,Cl,OH)

Ferruginous Sandstone (Ironstone) (Arenite with Limonite/Goethite cement) — sedimentary

Ferruginous Sandstone (Ironstone)

Arenite with Limonite/Goethite cement

Amethyst (Amethyst (SiO2 - Silicon Dioxide with iron impurities)) — mineral

Amethyst

Amethyst (SiO2 - Silicon Dioxide with iron impurities)

Chert (Microcrystalline Quartz (SiO2)) — sedimentary

Chert

Microcrystalline Quartz (SiO2)

River Pebble (Quartz/Jasper) (Silicon Dioxide (SiO2)) — sedimentary

River Pebble (Quartz/Jasper)

Silicon Dioxide (SiO2)

Septarian Nodule (Septaria) (Septarian Nodule (Calcium Carbonate/Aragonite/Calcite Concretion)) — sedimentary

Septarian Nodule (Septaria)

Septarian Nodule (Calcium Carbonate/Aragonite/Calcite Concretion)

Yellow Chert (River Stone/Pebble) (Chert (Cryptocrystalline Quartz, SiO2)) — sedimentary

Yellow Chert (River Stone/Pebble)

Chert (Cryptocrystalline Quartz, SiO2)

Chert (often called Flint or Jasper based on color) (Microcrystalline Silica (SiO2)) — sedimentary

Chert (often called Flint or Jasper based on color)

Microcrystalline Silica (SiO2)

Chert (Jasper/Flint variant) (Silicon Dioxide (SiO2)) — sedimentary

Chert (Jasper/Flint variant)

Silicon Dioxide (SiO2)

Chert (often called Flint or Agate nodule) (Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (often called Flint or Agate nodule)

Cryptocrystalline Quartz (SiO2)

Jasper (Iron-stained) (Silicon Dioxide (SiO2) with iron oxide inclusions) — sedimentary

Jasper (Iron-stained)

Silicon Dioxide (SiO2) with iron oxide inclusions

Chert (often called Flint) (Chert (Cryptocrystalline Silica, SiO2)) — sedimentary

Chert (often called Flint)

Chert (Cryptocrystalline Silica, SiO2)

Flint (Chert (Silicon dioxide, SiO2)) — sedimentary

Flint

Chert (Silicon dioxide, SiO2)

Pyrite (Iron Pyrite (FeS₂)) — Mineral

Pyrite

Iron Pyrite (FeS₂)

Carnelian (Carnelian (Silicon Dioxide: SiO2)) — mineral

Carnelian

Carnelian (Silicon Dioxide: SiO2)

Dalmation Stone (often called Dalmatian Jasper) (Peralkaline Rock (Microgranite/Aplite), SiO2 with inclusions of Arfvedsonite) — igneous

Dalmation Stone (often called Dalmatian Jasper)

Peralkaline Rock (Microgranite/Aplite), SiO2 with inclusions of Arfvedsonite

Chert (often referred to as Flint or Jasper when pigmented) (Microcrystalline or cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (often referred to as Flint or Jasper when pigmented)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Sandstone (Arenite (primarily SiO2)) — sedimentary

Sandstone

Arenite (primarily SiO2)

Limonite (Iron Ore) (Limonite (FeO(OH)·nH2O)) — mineral

Limonite (Iron Ore)

Limonite (FeO(OH)·nH2O)

Anthracite Coal (Anthracite (high-rank coal)) — metamorphic

Anthracite Coal

Anthracite (high-rank coal)

Yellow Jasper (Silicon Dioxide (SiO2) with iron hydroxides) — sedimentary

Yellow Jasper

Silicon Dioxide (SiO2) with iron hydroxides

Chert (Yellow Jasper/Agatized Chert) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Yellow Jasper/Agatized Chert)

Microcrystalline Quartz (SiO2)

Hematite (Iron(III) oxide (Fe2O3)) — mineral

Hematite

Iron(III) oxide (Fe2O3)

Satin Spar (often marketed as Selenite) (Fibrous Gypsum (Calcium Sulfate Dihydrate) - CaSO4·2H2O) — mineral

Satin Spar (often marketed as Selenite)

Fibrous Gypsum (Calcium Sulfate Dihydrate) - CaSO4·2H2O

Halite (Sodium Chloride (NaCl)) — Mineral

Halite

Sodium Chloride (NaCl)

Quartz Geode (Silicon Dioxide (SiO2) in a Secondary Sedimentary/Volcanic cavity) — mineral

Quartz Geode

Silicon Dioxide (SiO2) in a Secondary Sedimentary/Volcanic cavity

Fluorite (translucent octahedral crystal) (Calcium fluoride (CaF2)) — mineral

Fluorite (translucent octahedral crystal)

Calcium fluoride (CaF2)

Quartz Geode (Silicon Dioxide (SiO2)) — Mineral/Sedimentary

Quartz Geode

Silicon Dioxide (SiO2)

Mineral/Sedimentary

Green Calcite (Calcium Carbonate (CaCO3)) — mineral

Green Calcite

Calcium Carbonate (CaCO3)

Banded Agate (with Quartz Geode Center) (Silicon Dioxide (SiO2)) — mineral

Banded Agate (with Quartz Geode Center)

Silicon Dioxide (SiO2)