Slate
Slate (Foliated metamorphic rock)
Category
Browse organic (anthropogenic) specimens identified by the Rock Identifier community.
Slate
Slate (Foliated metamorphic rock)
Mookaite Jasper
Silicified Radiolarite (SiO2)
Limestone with Quartz/Calcite Veins
Sedimentary Limestone (CaCO3 with SiO2 or CaCO3 intrusions)
Petrified Wood
Silicified Wood (primarily SiO2)
Coral Fossil (Petrified Coral)
Scleractinia (Order) - Calcified Fossil Skeleton (CaCO3)
Jasper (specifically Yellow Jasper and Red Jasper)
Silicon Dioxide (SiO2) with iron oxide inclusions
Banded Chert (with Quartz Vein)
Microcrystalline Silica (SiO2)
Anthracite Coal
Anthracite (Carbon-rich metamorphic coal)
Chert (Chert Nodule)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Massive Cryptocrystalline Quartz (Chert/Chalcedony Pebble)
Silicon Dioxide (SiO2)
Travertine (often colloquially called Tufa)
Chemical Sedimentary Calcium Carbonate (CaCO3)
Chert (specifically Iron-stained River Cobble)
Silicon Dioxide (SiO2)
Chert (Jasper variety)
Silicon Dioxide (SiO2)
Petrified Wood
Silicified Wood (primarily Quartz / Chalcedony: SiO2)
Green Banded Chert (Agate/Jasper)
Silicon Dioxide (SiO2) with trace impurities of Chlorite or Glauconite
Coquina
Biogenic Limestone (Calcium Carbonate, CaCO3)
Graphite
Graphite (Native Carbon, C)
Chert (Nodule)
Silicon Dioxide (SiO2)
Chert (Cherty Flint/Jasper variety)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Shale (sub-type: Carbonaceous Shale)
Lutaceous Sedimentary Rock
Septarian Nodule or Mud Crack Fossil
Septarian Nodule (Concretion)
Chert (variations include Flint or Jasper)
Silicon Dioxide (SiO2)
Jasper
Agate/Jasper (Microcrystalline Quartz, SiO2)
Jasper (Mookaite variety likely)
Silicon Dioxide (SiO2) with iron oxide inclusions
Septarian Nodule (Dragon Stone)
Septarian Concretion (CaCO3 with Siderite and Calcite)
Banded Chert (Ironstone/Jasper)
Cryptocrystalline Quartz (SiO2) with Iron Oxides
Jasper
Silicon Dioxide (SiO2) with iron oxide impurities
Petrified Wood
Silicified Wood (SiO2)
Limestone
Calcium Carbonate (CaCO3)
Chert (Jasper variation)
Chert (SiO2)
Septarian Nodule (Dragon Stone)
Septarian Geode (CaCO3 + Mg + Fe)
Chert (Yellow Jasper variant)
Microcrystalline Quartz (SiO2)
Chert (Brecciated or Veined)
Silicon Dioxide (SiO2)
Chert (Iron-Stained)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Petrified Wood
Silicified Wood (primarily SiO2)
Moss Agate
Chalcedony (Silicon Dioxide with inclusions) - SiO2
Shale with Vein Infillings
Shale (a fine-grained clastic sedimentary rock). The veins could be Calcite (CaCO3), Quartz (SiO2), or other minerals.
Fossilized Wood (with Coal and Limonite)
Petrified Wood (Silicified or Carbonized Flora)
Petrified Wood
Silicified Wood (primarily SiO2)
Petrified Wood
Silicified Wood (SiO2)
Petrified Wood
Silicified Wood (primarily SiO2 - Silicon Dioxide)
Chert (often called Flint when dark)
Microcrystalline or Cryptocrystalline Quartz (SiO2)