Pyrite
Iron Sulfide (FeS2)
Category
Browse organic crystal (mineraloid) specimens identified by the Rock Identifier community.
Pyrite
Iron Sulfide (FeS2)
Chert (variously known as Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Ironstone Concretion
Siderite or Goethite Concretion
Pyrite in Shale
Iron Disulfide (FeS2) in Sedimentary Shale
Chert (Blue-Gray Chert)
Microcrystalline quartz (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Shale with Pyrite
Clastic sedimentary rock containing Iron Disulfide (FeS2)
Chert (Jasper/Flint variant)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Septarian Nodules-like)
Silicon dioxide (SiO2)
Chert (within Asphalt)
Chert (SiO2)
Chert (often called Flint or River Rock)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (White Chert)
Silicon Dioxide (SiO2)
Chert (potentially Jasper/Common Opal mixture)
Microcrystalline Quartz (SiO2)
Chert (Flint nodule)
Chert (SiO2)
Graphite
Graphite (Chemical Formula: C)
Chert (River Pebble)
Chert (Silicon Dioxide, SiO2)
Banded Chert (Jasper)
Silicon Dioxide (SiO2)
Chert (Jasper variety)
Cryptocrystalline Quartz (SiO2)
Quartzite river stone
Quartzite (SiO2)
Amber
Succinicum (Organic polymer, largely C10H16O)
Bituminous Coal
Organic sedimentary rock (humic coal)
Amber
Succinite (Fossilized Tree Resin) - C10H16O
Yellow Jasper
Silicon Dioxide (SiO2)
Glauconitic Sandstone (Greenstone)
Glauconitic Siliciclastic Sandstone (K,Na)(Fe,Al,Mg)2(Si,Al)4O10(OH)2
Chert (Nodule)
Silicon Dioxide (SiO2)
Petrified Wood
Silicified Wood (Permineralized organic tissue)
Ironstone Concretion (Moqui Marble / Boji Stone)
Sedimentary Iron Oxide Concretion (Fe2O3 / FeO(OH))
Limestone with Fossil Inclusions
Sedimentary Carbonate Rock (CaCO3)
Jasper
Silicon Dioxide (Microcrystalline Quartz, SiO2)
Petrified Wood
Silicified Wood (SiO2)
Limestone (Travertine/Tufa variant)
Calcium Carbonate (CaCO3)
Jasper (Iron-stained Chert)
Silicon Dioxide (SiO2) with iron oxide inclusions
Moss Agate Sphere
Silicon Dioxide (SiO2) with inclusions
Moss Agate
Silicon Dioxide with inclusions (SiO2 + Fe/Mn/Mg)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Jasper
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Chert (Flint Nodules)
Silicon Dioxide (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Chert (often called Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert / Flint
Chert (SiO2)
Pyrite in Limestone
Iron Sulfide (FeS2) in Calcium Carbonate (CaCO3)