Rock Identifier

Category

Organic Crystal (Mineraloid)

Browse organic crystal (mineraloid) specimens identified by the Rock Identifier community.

Glauconitic Sandstone (Glauconitic Quartz-Wacke / Sandstone (Fe(II),Fe(III),Al,Mg)2-3(Si,Al)4O10(OH)2) — sedimentary

Glauconitic Sandstone

Glauconitic Quartz-Wacke / Sandstone (Fe(II),Fe(III),Al,Mg)2-3(Si,Al)4O10(OH)2

Moss Agate (Silicon Dioxide (SiO2) with inclusions of hornblende, chlorite, or manganese/iron oxides) — mineral

Moss Agate

Silicon Dioxide (SiO2) with inclusions of hornblende, chlorite, or manganese/iron oxides

Petrified Wood (Silicified Wood (SiO2)) — sedimentary

Petrified Wood

Silicified Wood (SiO2)

Chert (Smooth River Pebble) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (Smooth River Pebble)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Petrified Wood (Silicified Wood (SiO2)) — metamorphic

Petrified Wood

Silicified Wood (SiO2)

Petrified Wood (Silicified Wood (SiO2)) — sedimentary

Petrified Wood

Silicified Wood (SiO2)

Chert (White/Light Tan) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (White/Light Tan)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Petrified Wood (Silicified wood (Quartz/Chalcedony - SiO2)) — sedimentary

Petrified Wood

Silicified wood (Quartz/Chalcedony - SiO2)

Septarian Nodule (Septarian Concretion (CaCO3 with Siderite/Calcite/Aragonite)) — sedimentary

Septarian Nodule

Septarian Concretion (CaCO3 with Siderite/Calcite/Aragonite)

Chert (Hag Stone / Hole Stone) (Chert (Cryptocrystalline variety of Quartz, SiO2)) — sedimentary

Chert (Hag Stone / Hole Stone)

Chert (Cryptocrystalline variety of Quartz, SiO2)

Chert (Nodular) (Chert (SiO2 - Microcrystalline Quartz)) — sedimentary

Chert (Nodular)

Chert (SiO2 - Microcrystalline Quartz)

Petrified Wood (Silicified Wood (SiO2)) — sedimentary

Petrified Wood

Silicified Wood (SiO2)

Petrified Wood (Agatized/Silicified Wood) (Silicified Wood (SiO2)) — metamorphic

Petrified Wood (Agatized/Silicified Wood)

Silicified Wood (SiO2)

Chert (specifically Tan/Brown Chert) (Chert (SiO2)) — sedimentary

Chert (specifically Tan/Brown Chert)

Chert (SiO2)

Banded Chert (Microcrystalline Quartz (SiO2)) — sedimentary

Banded Chert

Microcrystalline Quartz (SiO2)

Goldstone (Aventurine glass (Synthetic glass with copper inclusions)) — mineraloid / man-made glass

Goldstone

Aventurine glass (Synthetic glass with copper inclusions)

mineraloid / man-made glass

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

Jasper

Jasper (Silicon Dioxide, SiO2)

Banded Chert (Jasper) (Silicon Dioxide (SiO2)) — sedimentary

Banded Chert (Jasper)

Silicon Dioxide (SiO2)

Dendritic Opal (Common Opal) (Amorphous Hydrated Silica (SiO2·nH2O) with Manganese or Iron Oxide inclusions) — mineral

Dendritic Opal (Common Opal)

Amorphous Hydrated Silica (SiO2·nH2O) with Manganese or Iron Oxide inclusions

Green Jasper (with Quartz veining) (Jasper (Silica-rich microcrystalline variety of Quartz), formula: SiO2) — sedimentary

Green Jasper (with Quartz veining)

Jasper (Silica-rich microcrystalline variety of Quartz), formula: SiO2

Jasper (likely Brown or Brecciated) (Jasper (Silicon Dioxide, SiO2)) — sedimentary

Jasper (likely Brown or Brecciated)

Jasper (Silicon Dioxide, SiO2)

Fossiliferous Limestone (containing Brachiopods) (Biogenic Limestone (Calcium Carbonate, CaCO3)) — sedimentary

Fossiliferous Limestone (containing Brachiopods)

Biogenic Limestone (Calcium Carbonate, CaCO3)

Petrified Wood (Silicified Wood (SiO2)) — metamorphic

Petrified Wood

Silicified Wood (SiO2)

Quartz Geode (Silicon Dioxide (SiO2)) — sedimentary

Quartz Geode

Silicon Dioxide (SiO2)

Glauconitic Sandstone (or Greensand) (Glauconitic Siliciclastic Rock (Containing (K,Na)(Fe,Al,Mg)2(Si,Al)4O10(OH)2)) — sedimentary

Glauconitic Sandstone (or Greensand)

Glauconitic Siliciclastic Rock (Containing (K,Na)(Fe,Al,Mg)2(Si,Al)4O10(OH)2)

Banded Chert (Cryptocrystalline Quartz (SiO2)) — sedimentary

Banded Chert

Cryptocrystalline Quartz (SiO2)

Cullet Glass (Strawberry Glass) (Amorphous Silicon Dioxide (SiO2) with metallic dopants) — Mineraloid (Synthetic/Man-made)

Cullet Glass (Strawberry Glass)

Amorphous Silicon Dioxide (SiO2) with metallic dopants

Mineraloid (Synthetic/Man-made)

Petrified Wood (Silicified Wood (SiO2 - Silicon Dioxide)) — mineral

Petrified Wood

Silicified Wood (SiO2 - Silicon Dioxide)

Mookaite Jasper (Silicified Radiolarite (SiO2)) — sedimentary

Mookaite Jasper

Silicified Radiolarite (SiO2)

Chert (varietal: Jasper or Flint likely, but definitive identification is difficult from image) (SiO₂ (silicon dioxide)) — Sedimentary

Chert (varietal: Jasper or Flint likely, but definitive identification is difficult from image)

SiO₂ (silicon dioxide)

Red Jasper (Silicon dioxide (SiO2) with Iron Oxide (Fe2O3) inclusions) — sedimentary

Red Jasper

Silicon dioxide (SiO2) with Iron Oxide (Fe2O3) inclusions

Petrified Wood (Silicified wood (primarily Silicon Dioxide - SiO2)) — metamorphic

Petrified Wood

Silicified wood (primarily Silicon Dioxide - SiO2)

Chert (specifically Jasper or Flint) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (specifically Jasper or Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Petrified Wood (Silicified Wood (SiO2)) — sedimentary

Petrified Wood

Silicified Wood (SiO2)

Chert (Chert Nodule) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (Chert Nodule)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Yellow Chalcedony (common opal or chert variant) (Silicon Dioxide (SiO2)) — sedimentary (mineraloid/microcrystalline quartz)

Yellow Chalcedony (common opal or chert variant)

Silicon Dioxide (SiO2)

sedimentary (mineraloid/microcrystalline quartz)

Moss Agate (Chalcedony (Silicon Dioxide with inclusions) - SiO2) — mineral

Moss Agate

Chalcedony (Silicon Dioxide with inclusions) - SiO2

Massive Cryptocrystalline Quartz (Chert/Chalcedony Pebble) (Silicon Dioxide (SiO2)) — sedimentary

Massive Cryptocrystalline Quartz (Chert/Chalcedony Pebble)

Silicon Dioxide (SiO2)

Chert (Grey-Green Var.) (Silicon Dioxide (SiO2)) — sedimentary

Chert (Grey-Green Var.)

Silicon Dioxide (SiO2)

Shale (Shale (fine-grained clastic sedimentary rock)) — Sedimentary

Shale

Shale (fine-grained clastic sedimentary rock)

Travertine (Tufa) (Calcium Carbonate (CaCO3)) — sedimentary

Travertine (Tufa)

Calcium Carbonate (CaCO3)

Moss Agate (Silicon Dioxide with inclusions (SiO2 + impurities)) — mineral

Moss Agate

Silicon Dioxide with inclusions (SiO2 + impurities)