Prehnite
Prehnite - Ca2Al(AlSi3O10)(OH)2
Category
Browse mineral and metamorphic rock specimens identified by the Rock Identifier community.
Prehnite
Prehnite - Ca2Al(AlSi3O10)(OH)2
Red Sandstone (Old Red Sandstone)
Ferruginous Sandstone (SiO2 + Fe2O3)
Amygdaloidal Basalt with Zeolite/Quartz Infill
Amygdaloidal Basalt (Host: (Mg,Fe)2SiO4 / CaAl2Si2O8; Infill: SiO2 or Na2Al2Si3O10·2H2O)
Peach Moonstone
Orthoclase Feldspar (KAlSi3O8)
Basalt with Vesicles
Vesicular Basalt (comprising Plagioclase Feldspar, Pyroxene, and Olivine)
Bauxite
Bauxite (Al(OH)3, AlO(OH))
Basalt
Basalt (extrusive igneous rock)
Smoky Quartz
Silicon Dioxide (SiO₂)
Aquamarine
Beryl (Be3Al2Si6O18)
Smoky Quartz (with complementary stones in jewelry setting)
Smoky Quartz (Silicon Dioxide - SiO2)
Banded Agate (White Agate)
Chalcedony (Silicon Dioxide, SiO2)
Aquamarine
Beryl (Be3Al2Si6O18)
Smoky Quartz
Silicon Dioxide (SiO2)
Amethyst
Amethyst (Silicon Dioxide, SiO2)
Citrine
Silicon dioxide (SiO2)
Clear Quartz
Silicon Dioxide (SiO2)
Smoky Quartz
Quartz (Silicon Dioxide) - SiO2
Smoky Quartz
Silicon Dioxide (SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Rhodonite
Rhodonite (Manganese Silicate), (Mn,Fe,Mg,Ca)SiO3
Smoky Quartz
Silicon Dioxide (SiO2) with aluminum impurities
Milky Quartz
Silicon Dioxide (SiO2)
Native Gold (in Jewelry)
Gold (Au)
Smoky Quartz
Smoky Quartz (Silicon Dioxide, SiO2)
Greenstone (Epidote/Chlorite Schist)
Metabasalt (composed primarily of Epidote Ca2Al2(Fe3+;Al)(SiO4)(Si2O7)O(OH) and Chlorite (Mg,Fe)3(Si,Al)4O10(OH)2·(Mg,Fe)3(OH)6)
Mixed Gemstone Beaded Jewelry
Various minerals (e.g., Quartz varieties like Rose Quartz, Amethyst; Peridot; Garnet; etc.)
River Rock
Sedimentary Rock (various compositions)
Sandstone (Ferruginous)
Arenite with Iron Oxide cement (SiO2 + Fe2O3)
Agate
Silicon Dioxide (SiO2)
Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
Amethyst
Silicon Dioxide (SiO2) with iron impurities
Pyrite on Quartz
Iron Sulfide (FeS2) on Silicon Dioxide (SiO2)
Lepidolite
K(Li,Al)3(Si,Al)4O10(F,OH)2
Orthoclase Feldspar
Potassium aluminum silicate (KAlSi3O8)
Smoky Quartz
Smoky Quartz (Silicon Dioxide - SiO2)
Quartz River Cobble
Silicon Dioxide (SiO2)
Milky Quartz
Crystalline Silicon Dioxide (SiO2)
Basalt with Quartz/Feldspar Inclusions
Amygdaloidal or Porphyritic Mafic Volcanic Rock with Siliceous Veining
Amygdaloidal Basalt with Agate/Chalcedony Infills
Amygdaloidal Basalt (Composition: SiO2 and (Mg,Fe)2SiO4 in matrix; SiO2 in amygdule)
Limestone Breccia
Sedimentary Breccia (Calcareous)
Garnet and Quartz
Pyrope or Almandine (Red Garnets) and Quartz (Center Stone)
Shale
Fissile mudrock (composed primarily of clay minerals and quartz)