Pink Opal
Hydrated silica (SiO2 "n H2O)
Category
Browse organic (mineraloid) specimens identified by the Rock Identifier community.
Pink Opal
Hydrated silica (SiO2 "n H2O)
Green Moss Agate
Silicon Dioxide with inclusions (SiO2 + Mn/Fe)
Honey Calcite
Calcium Carbonate (CaCO3)
Chert (often called Jasper or River Siltstone)
Microcrystalline Quartz (SiO2)
Petrified Wood (Agatized/Silicified Wood)
Silicified Wood (SiO2)
Black Freshwater Pearls
Biogenic Calcium Carbonate (Aragonite/Calcite), CaCO3
Tree Agate
Silicon Dioxide (SiO2) with Dendritic Inclusions
Travertine
Tufa limestone (CaCO3)
Green Moss Agate
Agate (Silicon Dioxide - SiO2 with inclusions of Manganese/Iron oxides)
Limestone (Fossiliferous)
Calcium Carbonate (CaCO3)
Angel Skin Coral
Corallium rubrum / Corallium spp. (Calcium Carbonate, CaCO3)
Dendritic Agate
Silicon Dioxide with inclusions (SiO2 + Mn/Fe)
Sand Tiger Shark Tooth
Carcharias taurus
Petrified Wood
Silicified Wood (SiO2)
Fossiliferous Limestone (Coral Fossil)
Scleractinian Coral in Calcium Carbonate (CaCO3)
Jasper
Microcrystalline Quartz (SiO2)
Fossilized Bone
Permineralized Bone (Vertebrate Fossil)
Fossilized Bone
Permineralized Vertebrate Bone
Mammoth or Mastodon Tooth Fragment
Mammuthus / Mammut molar fragment
Limestone with Fossil
Sedimentary limestone, calcium carbonate (CaCO3)
Jasper
Silicon Dioxide (SiO2) microcrystalline quartz
Jasper
Silicon Dioxide (SiO2) with impurities
Shark Tooth Fossil
Carcharocles megalodon or similar fossilized shark tooth
Limestone (Crushed Gravel)
Limestone (Calcium Carbonate, CaCO3)
Sandstone
Arenite
Fossiliferous Limestone
Sedimentary Limestone (CaCO3) containing Crinoid or Brachiopod remains
Chert (Flint)
Silicon dioxide (SiO2)
Chert / Flint
Silicon Dioxide (SiO2)
Chert (Nodule)
Cryptocrystalline Quartz (SiO2)
Petrified Wood
Silicified Wood (primarily Chalcedony/Quartz, SiO2)
Chert Arrowhead
Chert (Cryptocrystalline variety of Quartz, SiO2)
Yellow Jasper
Silicon Dioxide (Microcrystalline Quartz, SiO2)
Jasper
Microcrystalline Quartz (SiO2)
Jasper
Microcrystalline Quartz (SiO2)
Limestone Concretion (Botryoidal/Calcareous Nodules)
Calcium Carbonate Concretion (CaCO3)
Limestone
Calcium Carbonate (CaCO3)
Petrified Wood
Silicified Wood (mainly Quartz/Chalcedony, SiO2)
Chert Cobble / Quartzite River Stone
Microcrystalline Quartz (SiO2) / Quartzite
Fossiliferous Limestone
Calcium carbonate matrix with macrofossils (CaCO3)
Chert (Flint)
Silicon Dioxide (SiO2)
Chert (Quartz)
Silicon dioxide (SiO2)
Chert (Chalcedony/Agate Pebble)
Cryptocrystalline Silica (SiO2)