Porphyritic Basalt or Diabase with Plagioclase Phenocrysts
Porphyritic Basalt or Diabase; Mineral: Plagioclase Feldspar
Category
Browse mineral pseudomorph specimens identified by the Rock Identifier community.
Porphyritic Basalt or Diabase with Plagioclase Phenocrysts
Porphyritic Basalt or Diabase; Mineral: Plagioclase Feldspar
Oolite or Oolitic Limestone
Oolitic Limestone (Principal mineral: Calcite, CaCO3)
Amygdaloidal Basalt
Amygdaloidal Basalt (Mafic volcanic rock)
Schist (Biotite/Mica Schist)
Medium-grade regional metamorphic rock (rich in Phyllosilicates)
Magnetite (Lodestone)
Magnetite (Fe3O4)
Snowflake Obsidian
Vitreous volcanic silicate (SiO2 with Cristobalite inclusions)
Ironstone Concretion (Moqui Marble Type)
Goethite/Hematite-cemented Sandstone Concretion
Pyrite (Fool's Gold)
Iron Disulfide (FeS2)
Calcite
Calcite (Calcium Carbonate, CaCO3)
Milky Quartz (Vein Quartz)
Silicon Dioxide (SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Diamond
Diamond (pure Carbon, C)
Rough Diamond
Diamond (pure carbon, C)
Halite
Halite (Sodium Chloride, NaCl)
Diamond (in a gold ring setting)
Carbon (C)
Rhodonite (in matrix)
Rhodonite (Mn,Fe,Mg,Ca)SiO3
Greenschist
Greenschist (Major minerals include Chlorite, Actinolite, and Epidote)
Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
Serpentinite
Serpentinite (composed primarily of Serpentine group minerals: (Mg,Fe)3Si2O5(OH)4)
Shale
Fissile Mudstone (primarily composed of clay minerals and quartz)
Sandstone Concretion
Clastic Sedimentary Rock (primarily SiO2 with mineral cement)
Fluorite
Calcium Fluoride (CaF2)
Mixed collection of minerals and rocks (Jasper, Carnelian, Granite, and Quartz)
Silicon Dioxide (SiO2) with varying impurities for silicates and igneous aggregates
Schist
Mica Schist
Amethyst
Amethyst (Silicon Dioxide - SiO2 with iron impurities)
Milky Quartz
Silicon Dioxide (SiO2)
Emerald
Beryl (Be3Al2(SiO3)6) with Chromium/Vanadium impurities
Smoky Quartz
Silicon Dioxide (SiO2)
Rose Quartz
Silicon Dioxide (SiO2)
Aquamarine
Beryl (Be3Al2Si6O18)
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Quartz (Smoky/Milky Variety)
Silicon Dioxide (SiO2)
Spessartine Garnet
Manganese aluminum silicate (Mn2+3Al2(SiO4)3)
Smoky Quartz
Silicon Dioxide (SiO2)
Sodalite
Sodalite (Na8(Al6Si6O24)Cl2)
Blue Calcite
Calcium Carbonate (CaCO3)
Stichtite (often found in Serpentinite)
Stichtite Mg6Cr2CO3(OH)16·4H2O
Quartz (Smoky/Milky variety with matrix)
Silicon Dioxide (SiO2)
Black Tourmaline in Quartz Matrix
Schorl (NaFe3Al6(BO3)3Si6O18(OH)4) with Quartz (SiO2)
Quartz
Silicon Dioxide (SiO2)
Fuchsite
Chromium-rich Muscovite (K(Al,Cr)2(AlSi3O10)(OH)2)
Larimar
Pectolite [NaCa2Si3O8(OH)] with copper substitution