Prehnite
Prehnite - Ca2Al(AlSi3O10)(OH)2
Category
Browse organic mineral specimens identified by the Rock Identifier community.
Prehnite
Prehnite - Ca2Al(AlSi3O10)(OH)2
Thunderegg (specifically a Jasper/Agate-filled Geode nodule)
Silicon Dioxide (SiO2) within Rhyolitic Matrix
Amethyst
Silicon Dioxide (SiO2) with iron impurities
Smoky Quartz
Silicon Dioxide (SiO2)
Amazonite
Microcline (Amazonstone), K(AlSi3O8)
Amethyst
Silicon Dioxide (SiO2) with iron impurities
Agate Geode
Chalcedony (cryptocrystalline SiO2)
Amethyst
Silicon Dioxide (SiO2) with iron impurities
Sandstone with Liesegang Rings
Arenite with Iron Oxide Concretions
Rose Quartz
Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese
Gold (Elemental Metal)
Gold (Au)
Rough Emerald
Emerald (Beryl), Be3Al2(SiO3)6
Gneiss (specifically Biotite Gneiss)
Gneiss (high-grade metamorphic rock primarily composed of Silicates)
Chrysocolla in Matrix
Hydrated copper phyllosilicate mineral (Cu,Al)2H2Si2O5(OH)4·nH2O
Chrysocolla on Matrix
Hydrated copper phyllosilicate mineral (Cu,Al)2H2Si2O5(OH)4·nH2O
Lepidolite (likely)
K(Li,Al)3(Al,Si)4O10(F,OH)2 (Phyllosilicate mineral, part of the mica group)
Epidote with Quartz and Feldspar
Ca2(Al2,Fe3+)(SiO4)3(OH) (Epidote complex)
Blue Apatite
Chlorapatite / Fluorapatite (Ca5(PO4)3(F,Cl,OH))
Quartz Pebble
Silicon Dioxide (SiO2)
Desert Rose (Baryte or Selenite variant)
Barium Sulfate (BaSO4) or Gypsum (CaSO4·2H2O) with Sand inclusions
Basalt River Cobble
Basalt (Aphanitic Mafic Volcanic Rock)
Diorite
Intermediate plutonic igneous rock
Greywacke (River Slikenside)
Greywacke (Lithic Sandstone)
Limonite after Pyrite (Prophecy Stone or Ironstone Concretion)
Goethite/Limonite pseudomorph after Pyrite/Marcasite (FeO(OH)·nH2O)
Red Ochre (Hematite-rich Clay)
Limonitic/Hematitic Claystone (Fe2O3 with clay minerals)
Granite
Granite (Felsic Intrusive Igneous Rock)
Ruby
Corundum (mineral species), variety: Ruby (Al2O3 with Cr3+ as the chromophore)
Basalt
Mafic Igneous Rock (composed primarily of Pyroxene and Plagioclase Feldspar)
Slag (Industrial Glass Slag)
Amorphous Silicate Glass (often containing Al, Ca, Mg, and Ti oxides)
Quartzite
Quartzite (SiO2)
Basalt (Vesicular)
Basalt (Mafic Extrusive Igneous Rock)
Basalt
Extrusive mafic igneous rock
Glaucophane Schist (Blueschist)
Blueschist (Glaucophane-bearing schist)
Pyrite
Iron Sulfide (FeS2)
Chrysocolla
Chrysocolla; (Cu,Al)2H2Si2O5(OH)4·nH2O
Blue Calcite
Calcium Carbonate (CaCO3)
Pegmatite
Granitic Pegmatite
Green Aventurine (Tumbled Quartzite)
Silicon Dioxide (SiO2) with inclusions of Fuchsite
Sandstone (Quartzose)
Arenite (primarily SiO2)
Granitic Pegmatite with Schorl
Granitic Pegmatite (Schorl: NaFe3Al6(Si6O18)(BO3)3(OH)3OH)
Kyawthuite
Kyawthuite (Bi3+Sb5+O4)
Diamond
Diamond (C)