Concretion
Septarian Concretion
Category
Browse mineral like biological tissue specimens identified by the Rock Identifier community.
Concretion
Septarian Concretion
Larimar (Slab)
Pectolite [NaCa2Si3O8(OH)]
Petrified Wood
Silicified Wood (SiO2)
Smoky Quartz
Silicon Dioxide (SiO2)
Gossan
Ferruginous gossan (Iron-rich capping)
Quartz (Milky Quartz / Quartz Crystal)
Silicon Dioxide (SiO2)
Quartz Vein / Quartz Matrix
Silicon Dioxide (SiO2)
Gold in Quartz
Gold (Au) in Quartz (SiO2)
Banded Agate (Chert/Chaldcedony)
Silicon Dioxide (SiO₂)
Obsidian
Volcanic Glass (Primary composition: SiO2 - Silicon Dioxide)
Septarian Nodule
Septarian Nodule (Mixture of Calcite, Aragonite, and Limestone/Clay)
Petrified Wood
Silicified Wood (SiO2)
Fluorite
Calcium fluoride (CaF2)
Vesicular Basalt
Extrusive mafic igneous rock
Quartz Geode Fragment
Silicon Dioxide (SiO2)
Schist (Kyanite Schist)
Kyanite-Mica Schist (primarily Al2SiO5, KAl2(AlSi3O10)(OH)2, and SiO2)
Black Obsidian
Volcanic Glass (SiO2)
Petrified Wood
Silicified Wood (primarily Quartz/Chalcedony, SiO2)
Mahogany Obsidian
Volcanic Glass with Hematite/Magnetite (SiO2 + Fe2O3)
Limonite Concretion
Limonite (Hydrated iron(III) oxide-hydroxides, FeO(OH)·nH2O)
Quartz on Schist
Silicon Dioxide (SiO2) on Foliated Metamorphic Rock
Synthetic Marbled Aggregate (Footwear Component)
Ethylene-vinyl acetate (Croslite™)
Glaucophane Schist (Blueschist)
Blueschist (Glaucophane-bearing schist)
Quartz
Silicon Dioxide (SiO2)
Milky Quartz with Iron Inclusions
Silicon Dioxide (SiO2)
Fossilized Shark Tooth
Fossilized elasmobranch tooth (Apatite/Calcium Phosphate)
Petrified Wood
Silicified Wood (primarily SiO2)
Diorite (or Gabbro/Granitoid)
Diorite
Fossilized Shark Tooth (Fragment)
Elasmobranchii gen. et sp. indet. (Calcium Phosphate / Apatite fossil)
Granite
Granite
Granite
Granite (composed primarily of Quartz SiO2, Orthoclase KAlSi3O8, and Plagioclase NaAlSi3O8 to CaAl2Si2O8)
Desert Rose
Gypsum rosette (CaSO4·2H2O) or Barite rosette (BaSO4)
Gneiss
Gneiss (Metamorphic Rock)
Blue Quartzite (Dyed)
Metamorphosed Quartz-rich Sandstone (SiO2 with organic dye)
Serpentine
Antigorite, Lizardite, or Chrysotile; (Mg, Fe)3Si2O5(OH)4
Mahogany Obsidian
Volcanic glass (SiO2 with Hematite or Magnetite inclusions)
Lepidolite
K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2 (Lithium-bearing Phyllosilicate)
Green Schist
Greenschist (containing Chlorite, Actinolite, and Epidote)
Green Aventurine
Silicon Dioxide (Quartz variety with Fuchsite inclusions - SiO2)
Schist
Mica Schist
Ferruginous Quartz (Iron-stained Quartz)
Silicon Dioxide (SiO2) with iron oxide inclusions/staining (Limonite/Hematite)
Fluorite
Fluorite (Calcium Fluoride, CaF2)