Petrified Wood
Silicified wood (primarily Silicon Dioxide, SiO2)
Category
Browse organic mineraloid specimens identified by the Rock Identifier community.
Petrified Wood
Silicified wood (primarily Silicon Dioxide, SiO2)
Shale
Mudstone (composed primarily of clay minerals like kaolinite, illite, and smectite, with quartz and calcite)
Moss Agate
Silicon Dioxide (SiO2) with Manganese or Iron Oxide inclusions
Shale with Pyrite
Clastic sedimentary rock containing Iron Disulfide (FeS2)
Chert (Jasper/Flint variant)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Flint Nodules)
Microcrystalline Quartz (SiO2)
Amber
Succinite (Fossilized Tree Resin) - C10H16O
Moss Agate
Silicon Dioxide (SiO2) with inclusions
Cat's Eye Shell (Shiva Shell)
Operculum of the Turbo petholatus (Tapestry Turban Snail), predominantly Calcium Carbonate (Aragonite)
Ceramic or Polished Stone Heart (Anthropogenic Material)
Glazed Ceramic (Silicon Dioxide based coating on Alumina Silicate body) or Polished Limestone/Marble (Calcium Carbonate, CaCO3)
Tektite (Indochinite)
Tektite (High-silica natural glass)
Tektite (specifically Indochinite)
Tektite (Natural silica glass)
Ferruginous Slag (Iron Smelting Byproduct)
Fused Silicate Scoria (Amorphous mixture of FeO, SiO2, and CaO)
Red Jasper
Jasper (a variety of Chalcedony, SiO₂)
Cobalt Blue Sea Glass
Amorphous Silica Glass (SiO2 + CoO)
Red Slag Glass
Amorphous Silica (Industrial byproduct with metallic oxide dopants)
Opalite
Synthetic Opalite Glass (Silicon Dioxide)
Cullet Glass (sometimes mistaken for Blue Obsidian or Slag)
Amorphous Silicon Dioxide (SiO2) with chemical additives (e.g., Cobalt for blue color)
Slag Glass (Cullet)
Amorphous Silica (man-made), primarily SiO2 with trace metal oxides
Green Glass Slag
Amorphous Silicon Dioxide (SiO2) with metal oxide impurities
Green Slag Glass
Amorphous Silica / Glassy Blast Furnace Slag
Glass Nugget (Tumbled Glass)
Amorphous Silicon Dioxide (SiO2) with additives
Chert (Jasper-bearing)
Microcrystalline silica (SiO2) with iron oxide inclusions
Pyrite in Shale
Iron Sulfide (FeS2) in Sedimentary Matrix
Chert (Flint)
Silicon Dioxide (SiO2)
Green Jasper
Jasper (Silicates, SiO2)
Chert (Gravel)
Silicon Dioxide (SiO2)
Chert (Jasper/Common Opal mix)
Microcrystalline Quartz (SiO2)
Chert (Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (often called Flint when dark or worked)
Cryptocrystalline silica (SiO2)
Anthracite Coal
Anthracite (Carbon-rich metamorphic coal)
Chert (Yellow Jasper variant)
Silicon Dioxide (SiO2)
Chert (Yellow variety / Jasper)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Yellow/Brown variety)
Chert (SiO2)
Black Marble
Recrystallized Limestone (CaCO3)
Petrified Wood (Silicified Wood)
Silicified fossil wood (SiO2)
Chert (Yellow Jasper variant)
Microcrystalline Quartz (SiO2)
Chert (Arrowhead/Tool variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Limestone with Chert or Siltstone bands
Sedimentary carbonate rock (CaCO3) often with siliceous impurities
Chert (specifically Yellow/Tan Chert)
Silicon Dioxide (SiO2)
Chert (and Flint variant)
Microcrystalline Quartz (SiO2)
Pyrite (Fool's Gold)
Iron Disulfide (FeS2)