Prehnite
Prehnite (Ca2Al(AlSi3O10)(OH)2)
Category
Browse mineral like biological tissue specimens identified by the Rock Identifier community.
Prehnite
Prehnite (Ca2Al(AlSi3O10)(OH)2)
Prehnite
Prehnite (Ca2Al(AlSi3O10)(OH)2)
Amazonite (microcline feldspar)
K(AlSi3O8) - Potassium Aluminum Silicate
Petrified Wood
Silicified Wood (SiO2)
Diorite
Intermediate plutonic igneous rock
Slate with Iron Staining
Low-grade Metamorphic Mudstone (Slate)
Limonite Stained Basalt
Hydrated Iron Oxide on Mafic Volcanic Rock (FeO(OH)·nH2O)
Prehnite
Prehnite (Ca2Al2Si3O10(OH)2)
Travertine (Tufa)
Chemical Limestone (CaCO3)
Gneiss (Metamorphic Cobble)
Gneiss
Amygdaloidal Basalt
Amygdaloidal Basalt (Mafic Extrusive)
Mahogany Obsidian
Volcanic Glass with Hematite or Magnetite (SiO2 + Fe2O3)
Sulfur (with Matrix)
Native Sulfur (S8)
Quartz on Host Rock
Silicon Dioxide (SiO2)
Dendritic Agate
Chalcedony (Silicon Dioxide, SiO2) with Manganese/Iron oxide inclusions
Serpentinite
Serpentinite (composed primarily of Serpentine group minerals, Mg3Si2O5(OH)4)
Dendritic Agate (Tree Agate)
Chalcedony (Silicon Dioxide, SiO2) with Manganese or Iron Oxide inclusions
Ruby, Emerald, and Sapphire (Corundum and Beryl)
Corundum (Al2O3) and Beryl (Be3Al2Si6O18)
Muscovite Mica (with Quartz)
Muscovite (KAl2(AlSi3O10)(OH)2)
Red Garnet (likely Almandine or Pyrope)
Garnet group: X3Y2(SiO4)3 (e.g., Almandine: Fe3Al2Si3O12)
Biotite (Black Mica)
Biotite [K(Mg,Fe)3(AlSi3O10)(F,OH)2]
Sandstone
Arenite (primarily Quartz, SiO2)
Obsidian
Volcanic Glass (SiO2)
Vesicular Basalt with Amygdules
Amygdaloidal Basalt
Slag Glass
Anthropogenic Amorphous Silicon Dioxide
Tree Agate
Dendritic Agate (Silicon Dioxide, SiO2)
Greenstone (Greenstone River Pebble)
Greenschist (metamorphosed mafic igneous rock)
Fossil Shell (Bivalve)
Class Bivalvia (fossilized)
Amygdaloidal Basalt
Extrusive mafic igneous rock with amygdules
Greenstone
Greenschist / Greenstone (containing Chlorite, Epidote, Actinolite)
Amygdaloidal Basalt
Amygdaloidal Basalt containing Zeolite or Quartz (SiO2/Silicates)
Granitic Pegmatite
Pegmatite containing Quartz, Feldspar, and Muscovite mica
Rutilated Quartz (beads)
SiO2 with TiO2 inclusions (Titanium Dioxide inclusions within Quartz)
Quartz Vein in Sedimentary Rock
Silicon Dioxide (SiO2) with host Chert or Limestone
Sandstone (Picture Sandstone)
Arenite (primarily SiO2 with iron oxide impurities)
Biotite Schist
Biotite Schist
Sandstone
Arenite (SiO2 primarily)
Moss Agate
SiO2
Silver Nugget
Native Silver (Ag)
Agate (Chalcedony Nodule)
Silicon Dioxide (SiO2)
Chrysocolla
Hydrated copper phyllosilicate, (Cu,Al)2H2Si2O5(OH)4·nH2O
Tumbled Stone
Silicon dioxide / Various silicates