Chert (often called Flint when dark)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Category
Browse organic mineraloid specimens identified by the Rock Identifier community.
Chert (often called Flint when dark)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Petrified Wood
Silicified wood (primarily SiO2)
Chert / Jasper
Microcrystalline Quartz (SiO2)
Chert (specifically Green Chert/Jasper)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Chert (Jasper/Flint variety)
Microcrystalline Quartz (SiO2)
Chert (varieties include Flint and Jasper)
Silicon Dioxide (SiO2) / Microcrystalline Quartz
Shungite
Non-crystalline carbon (similar to anthracite coal or meta-anthracite)
Chert Concretion with Iron Oxide Staining
Microcrystalline Quartz (SiO2)
Chert
Microcrystalline Quartz (SiO2)
Black Jasper
Jasper (Silicon Dioxide, SiO2)
Chert (River Pebble)
Microcrystalline silica (SiO2)
Chert (Flint)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Chert (and Limestone)
Silicon Dioxide (SiO2) in Calcium Carbonate (CaCO3)
Chert with Iron Oxide Staining
Microcrystalline Quartz (SiO2) with Limonite/Goethite staining
Chert (often called Flint in dark varieties)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Iron-stained variant)
Microcrystalline Quartz (SiO2)
Chert (Jasper variety)
Silicon Dioxide (SiO2)
Picture Jasper
SiO2
Chert (Jasper)
Silicon Dioxide (SiO2)
Chert (Yellow or Brown Jasper)
Microcrystalline Quartz (SiO2)
Green Chert (Jasper)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Fossilized Oyster Shell (Limestone/Coquina)
Crassostrea (Fossilized Bivalve), Calcium Carbonate (CaCO3)
Chert (often called Flint)
Microcrystalline Quartz (SiO2)
Chalcedony
Cryptocrystalline Quartz (SiO2)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Chert (Jasper/Flint variety)
Silicon Dioxide (SiO2)
Chert (Flint variety)
Chert (Cryptocrystalline Quartz, SiO2)
Turquoise and Spiny Oyster (Heishi style beads)
Turquoise (CuAl6(PO4)4(OH)8·4H2O) and Spondylus (Spiny Oyster shell)
Moss Agate
Silicon Dioxide (SiO2) with inclusions of Manganese or Iron oxide
Tahitian Pearl
Biogenic Calcium Carbonate (Aragonite/Calcite), CaCO3
Moss Agate
Silicon Dioxide with inclusions (SiO2 + impurities)
Petrified Wood
Silicified Wood (primarily Quartz/Chalcedony, SiO2)
Limestone
Calcium Carbonate (CaCO3)
Ironstone Concretion
Siderite or Hematite Concretion
Limestone
Calcium carbonate (CaCO3)
Petrified Wood
Silicified Wood (primarily SiO2)
Amber
Succinite (Fossilized Tree Resin)
Shale
Shale (Fine-grained clastic sedimentary rock)
Lignite (Brown Coal)
Humic Lignite (Carbonaceous sedimentary rock)
Glauconite (Green Sandstone)
Glauconite (K,Na)(Fe,Al,Mg)2(Si,Al)4O10(OH)2
Limestone
Calcium Carbonate (CaCO3)
Fossiliferous Limestone
Biogenic Limestone (Calcium Carbonate, CaCO3)