Rock Identifier

Category

Organic Gemstone (Sedimentary Classification)

Browse organic gemstone (sedimentary classification) specimens identified by the Rock Identifier community.

Coquina (Biogenic Limestone (Calcium Carbonate, CaCO3)) — sedimentary

Coquina

Biogenic Limestone (Calcium Carbonate, CaCO3)

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

Chert (White/Light Tan)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Petrified Wood (Silicified Wood (primarily SiO2)) — sedimentary

Petrified Wood

Silicified Wood (primarily SiO2)

Picture Jasper (Silicon Dioxide (SiO2) with iron oxide and organic impurities) — sedimentary

Picture Jasper

Silicon Dioxide (SiO2) with iron oxide and organic impurities

Fossilized Wood (with Coal and Limonite) (Petrified Wood (Silicified or Carbonized Flora)) — sedimentary

Fossilized Wood (with Coal and Limonite)

Petrified Wood (Silicified or Carbonized Flora)

Quartz Crystal Fragment (Silicon Dioxide (SiO2)) — mineral

Quartz Crystal Fragment

Silicon Dioxide (SiO2)

Chert (variously identified as Flint) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (variously identified as Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Petoskey Stone (Hexagonaria percarinata (Fossilized Rugose Coral)) — sedimentary

Petoskey Stone

Hexagonaria percarinata (Fossilized Rugose Coral)

Septarian Nodule (Thunder Egg) (Septarian Concretion (CaCO3 + CaMg(CO3)2 + SiO2)) — sedimentary

Septarian Nodule (Thunder Egg)

Septarian Concretion (CaCO3 + CaMg(CO3)2 + SiO2)

Chert (Iron-stained) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (Iron-stained)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Limestone (Calcium Carbonate (CaCO3)) — sedimentary

Limestone

Calcium Carbonate (CaCO3)

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

Graphite (Graphite (Native Carbon, C)) — metamorphic

Graphite

Graphite (Native Carbon, C)

Petrified Wood (Silicified Wood (SiO2)) — sedimentary

Petrified Wood

Silicified Wood (SiO2)

Petrified Wood (Agatized/Silicified Wood) (Silicified Wood / Chalcedony (SiO2)) — sedimentary

Petrified Wood (Agatized/Silicified Wood)

Silicified Wood / Chalcedony (SiO2)

Chert (Flint) (Chert (Cryptocrystalline variety of Quartz, SiO2)) — sedimentary

Chert (Flint)

Chert (Cryptocrystalline variety of Quartz, SiO2)

Chert (specifically a stream-worn Chert Nodule) (Sedimentary Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (specifically a stream-worn Chert Nodule)

Sedimentary Cryptocrystalline Quartz (SiO2)

Chert (Flint Pebbles) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (Flint Pebbles)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Anthracite Coal (Anthracite) — metamorphic

Anthracite Coal

Anthracite

Petrified Wood (Silicified wood (Quartz, SiO2)) — metamorphic

Petrified Wood

Silicified wood (Quartz, SiO2)

Baltic Amber (Succinite (Polmerized conifer resin)) — mineraloid

Baltic Amber

Succinite (Polmerized conifer resin)

Septarian Nodule or Mud Crack Fossil (Septarian Nodule (Concretion)) — sedimentary

Septarian Nodule or Mud Crack Fossil

Septarian Nodule (Concretion)

Chert (variations include Flint or Jasper) (Silicon Dioxide (SiO2)) — sedimentary

Chert (variations include Flint or Jasper)

Silicon Dioxide (SiO2)

Jasper (Mookaite variety likely) (Silicon Dioxide (SiO2) with iron oxide inclusions) — sedimentary

Jasper (Mookaite variety likely)

Silicon Dioxide (SiO2) with iron oxide inclusions

Septarian Nodule (Dragon Stone) (Septarian Concretion (CaCO3 with Siderite and Calcite)) — sedimentary

Septarian Nodule (Dragon Stone)

Septarian Concretion (CaCO3 with Siderite and Calcite)

Banded Chert (Ironstone/Jasper) (Cryptocrystalline Quartz (SiO2) with Iron Oxides) — sedimentary

Banded Chert (Ironstone/Jasper)

Cryptocrystalline Quartz (SiO2) with Iron Oxides

Septarian Nodule (Dragon Stone) (Septarian Geode (CaCO3 + Mg + Fe)) — sedimentary

Septarian Nodule (Dragon Stone)

Septarian Geode (CaCO3 + Mg + Fe)

Chert (Yellow Jasper variant) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Yellow Jasper variant)

Microcrystalline Quartz (SiO2)

Chert (Brecciated or Veined) (Silicon Dioxide (SiO2)) — sedimentary

Chert (Brecciated or Veined)

Silicon Dioxide (SiO2)

Petrified Wood (Silicified Wood (SiO2)) — sedimentary

Petrified Wood

Silicified Wood (SiO2)

Caribbean Calcite (Calcium Carbonate with Argonite (CaCO3)) — mineral

Caribbean Calcite

Calcium Carbonate with Argonite (CaCO3)

Horse Chestnut (Buckeye seed) (Aesculus hippocastanum seed) — Organic (Non-geological)

Horse Chestnut (Buckeye seed)

Aesculus hippocastanum seed

Organic (Non-geological)

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

Chert (Smooth River Pebble)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Jasper with Quartz Vein (Silicon Dioxide (SiO2) - Microcrystalline Quartz) — sedimentary

Jasper with Quartz Vein

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Fossil Coral (Favosites Honeycomb) (Favosites (Genus), Phylum Cnidaria, Class Anthozoa) — sedimentary

Fossil Coral (Favosites Honeycomb)

Favosites (Genus), Phylum Cnidaria, Class Anthozoa

Petrified Wood (Silicified Wood (SiO2)) — sedimentary

Petrified Wood

Silicified Wood (SiO2)

Jasper (Iron-stained Chert) (Silicon Dioxide (SiO2) with impurities of Hematite or Goethite) — sedimentary

Jasper (Iron-stained Chert)

Silicon Dioxide (SiO2) with impurities of Hematite or Goethite

Asphalt (Bituminous pavement) (Bituminous concrete / Asphalt) — Sedimentary (Anthropogenic)

Asphalt (Bituminous pavement)

Bituminous concrete / Asphalt

Sedimentary (Anthropogenic)

Blue Chalcedony (Cryptocrystalline Quartz (SiO2)) — mineral

Blue Chalcedony

Cryptocrystalline Quartz (SiO2)

Quartz (Milky/Common) (Silicon Dioxide (SiO2)) — mineral

Quartz (Milky/Common)

Silicon Dioxide (SiO2)

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

Chert (Grey-Green Var.)

Silicon Dioxide (SiO2)

Diorite (Dalmatian Stone) (Phaneritic Plutonic Diorite) — igneous

Diorite (Dalmatian Stone)

Phaneritic Plutonic Diorite