Chert / Flint (with Crinoid Stem Molds)
Microcrystalline Quartz (SiO2)
Category
Browse organic (mineraloid) specimens identified by the Rock Identifier community.
Chert / Flint (with Crinoid Stem Molds)
Microcrystalline Quartz (SiO2)
Moss Agate
Chalcedony (Silicon Dioxide - SiO2) with inclusions
Petrified Wood
Silicified Wood (primarily SiO2)
Petrified Wood (Agatized/Silicified Wood)
Silicified Paleoxylon (primarily SiO2)
Fossiliferous Limestone
Biogenic Limestone (Calcium Carbonate, CaCO3)
Goldstone (Brown)
Aventurine glass
Opalite
Synthetic Opalized Glass
Tektite (Indochinite)
Tektite (High-silica natural glass)
Tektite (specifically Indochinite)
Tektite (Natural silica glass)
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)
Cobalt Blue Sea Glass
Amorphous Silica Glass (SiO2 + CoO)
Ferruginous Slag (Iron Smelting Byproduct)
Fused Silicate Scoria (Amorphous mixture of FeO, SiO2, and CaO)
Red Jasper
Jasper (a variety of Chalcedony, SiO₂)
Slag Glass (Cullet)
Amorphous Silica (man-made), primarily SiO2 with trace metal oxides
Red Slag Glass
Amorphous Silica (Industrial byproduct with metallic oxide dopants)
Opalite
Synthetic Opalite Glass (Silicon Dioxide)
Green Glass Slag
Amorphous Silicon Dioxide (SiO2) with metal oxide impurities
Cullet Glass (sometimes mistaken for Blue Obsidian or Slag)
Amorphous Silicon Dioxide (SiO2) with chemical additives (e.g., Cobalt for blue color)
Green Slag Glass
Amorphous Silica / Glassy Blast Furnace Slag
Glass Nugget (Tumbled Glass)
Amorphous Silicon Dioxide (SiO2) with additives
Ironstone Concretion
Siderite or Hematite Concretion
Quartzite river stone
Quartzite (SiO2)
Tufa (Calcareous Tufa)
Calcareous Tufa (Precipitated CaCO3)
Moss Agate with Jasper
Chalcedony (SiO2 with inclusions)
River Pebble (Siltstone/Mudstone)
Clastic sedimentary rock
Moss Agate
Chalcedony (Silicon Dioxide, SiO2) with inclusions of Chlorite, Manganese, or Iron
Jasper with Agate and Quartz Inclusions
Silicon Dioxide (SiO2) - Chalcedony / Quartz aggregate
Moss Agate
Silicon Dioxide with inclusions (SiO2)
Sandstone Pebble
Arenite (primarily SiO2)
Moss Agate
Silicon Dioxide (SiO2) with inclusions of manganese or iron oxide
Moss Agate
Silicon Dioxide with inclusions (SiO2 + Fe/Mn/Mg)
Petrified Wood
Silicified Wood (SiO2)
Chert Concretion with Iron Oxide Staining
Microcrystalline Quartz (SiO2)
Picture Jasper
SiO2
Chert (River Pebble)
Microcrystalline silica (SiO2)
Chert
Microcrystalline Quartz (SiO2)
Chert (White Chert/Flint)
Silicon Dioxide (SiO2)
Petrified Wood
Silicified wood (primarily SiO2)
Black Jasper (Etched)
Silicon Dioxide (SiO2) with impurities
Chert (Flint)
Chert (SiO2)
Chert (Green variety)
Silicon Dioxide (SiO2)