Prehnite
Prehnite (Ca2Al(AlSi3O10)(OH)2)
Category
Browse mineral like byproduct (technogenic) specimens identified by the Rock Identifier community.
Prehnite
Prehnite (Ca2Al(AlSi3O10)(OH)2)
Blue Quartzite
Silicon Dioxide (SiO2) with inclusions
Obsidian
Obsidian (Volcanic Glass, SiO2 + impurity)
Sandstone (specifically Banded Sandstone)
Clastic sedimentary rock (primarily SiO2)
Obsidian
Volcanic glass (high silica volcanic rock)
Flower Agate (Cherry Blossom Agate)
Chalcedony (SiO2) with Opaque Inclusions
Limonite
Limonite (Hydrated iron(III) oxide-hydroxide) FeO(OH)·nH2O
Sandstone (with Concretion)
Arenite / Quartzose Sandstone
Schist
Schist (Metamorphic Rock)
Septarian Nodule (Pebble)
Septarian concretion (composition: CaCO3, calcite, aragonite, and clay/mudstone)
Quartz Geode
Silicon Dioxide (SiO2)
Muscovite Mica
Muscovite (KAl2(AlSi3O10)(F,OH)2)
Quartz Geode
Silicon Dioxide (SiO2)
Limonite Sandstone
Ferruginous Sandstone (Hydrated Iron Oxide)
Gneiss
Gneiss
Greenstone or Epidote-rich Metamorphic Rock
Chlorite/Epidote Schist or Greenstone
Limonite (Ironstone) pseudomorph
Limonite (Hydrous ferric oxide), FeO(OH)·nH2O
Banded Gneiss
Gneiss (SiO2-rich metamorphic rock)
Greenstone
Metamorphosed Mafic Igneous Rock
Greenschist (containing Epidote and Quartz)
Greenschist (Epidote-Chlorite-Actinolite Schist)
Jasper with Hematite inclusions
Silicon Dioxide (SiO2) with Iron Oxide (Fe2O3)
Quartz Pebble (with Mica or Iron staining)
Silicon Dioxide (SiO2)
Amygdaloidal Basalt
Vesicular Basalt with Amygdules
Banded Quartzite or Gneissic Pebble
Quartzite with mafic inclusions (SiO2) or Banded Gneiss
Sodalite
Sodalite (Na8(Al6Si6O24)Cl2)
Red Vanadinite on Matrix
Vanadinite (Pb5(VO4)3Cl)
Conglomerate
Conglomerate (Clastic sedimentary rock)
Gneiss
Gneiss (High-grade Regional Metamorphic Rock)
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Chrysocolla (Copper Ore matrix)
Chrysocolla (Cu2-xAlx(H2-xSi2O5)(OH)4·nH2O)
Native Sulfur
Sulfur (S)
Quartz with Mica
SiO2 (Quartz) with Potassium aluminum silicate (Muscovite)
Aquamarine
Beryl (Be3Al2(SiO3)6)
Fossilized Shark Tooth (Otodus obliquus)
Otodus obliquus (Mineralized Apatite / Bio-apatite)
Botryoidal Goethite
Goethite (α-Fe3+O(OH))
Emerald
Beryl (Be3Al2(SiO3)6)
Fossilized Coral (Petoskey Stone or similar Rugose Coral)
Hexagonaria percarinata (or similar Rugose/Tabulate coral)
Ammonite Fossil
Ammonoidea (subclass)
Limonite after Pyrite (Prophecy Stone or Ironstone Concretion)
Goethite/Limonite pseudomorph after Pyrite/Marcasite (FeO(OH)·nH2O)
Sandstone (Red Sandstone)
Arenite
Fluorite Octahedron
Fluorite (Calcium Fluoride, CaF2)
Gneiss
Gneiss (High-grade metamorphic rock)