Prehnite
Prehnite (Ca2Al(AlSi3O10)(OH)2)
mineral
Category
Mineral (Primary Constituent)
Browse mineral (primary constituent) specimens identified by the Rock Identifier community.
Prehnite
Prehnite (Ca2Al(AlSi3O10)(OH)2)
mineral
Serpentinite
Serpentinite (composed primarily of Serpentine group minerals: (Mg,Fe)3Si2O5(OH)4)
metamorphic
Serpentinite
Serpentinite (composed primarily of Serpentine group minerals: (Mg,Fe)3Si2O5(OH)4)
metamorphic
Shale
Mudstone (composed primarily of clay minerals like kaolinite, illite, and smectite, with quartz and calcite)
sedimentary
Serpentinite
Serpentinite (composed primarily of Serpentine group minerals: (Mg,Fe)3Si2O5(OH)4)
metamorphic
Lapis Lazuli
Lapis Lazuli (a rock type, not a single mineral, composed primarily of lazurite, calcite, and pyrite)
Mineral, part of a rock
Green Fluorite
Fluorite (Calcium Fluoride, CaF2)
mineral
Limonite (Iron Ore)
FeO(OH)·nH2O
mineral
Diamond
Diamond (C)
Mineral
Epidote
Epidote Group (Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH))
metamorphic
Greenstone
Greenschist / Meta-basalt
metamorphic
Greenstone (Greenschist)
Greenschist (composed of Chlorite, Epidote, and Actinolite)
metamorphic
Greenstone
Greenschist / Greenstone (Chlorite-Epidote facies)
metamorphic
Limonite with Trace Fossils
Hydrous Iron Oxide Mixture (FeO(OH)·nH2O)
sedimentary
Quartz (Milky Quartz)
Quartz (Silicon Dioxide, SiO2)
mineral
Gold Flakes
Native Gold (Au)
mineral
Bumblebee Jasper
Fibrous Calcite with Arsenic and Sulfur inclusions
mineral
Dalmation Stone
Dalmation Jasper (Igneous microcrystalline quartz with arfvedsonite)
igneous
Black Tourmaline
Schorl (Sodium Iron Aluminum Borosilicate Hydroxide), NaFe3Al6(BO3)3Si6O18(OH)4
mineral
Tiger's Eye
Silicon Dioxide (SiO2)
Mineral
Pink Feldspar
Orthoclase Feldspar (KAlSi3O8)
mineral
Calcite
Calcium Carbonate (CaCO3)
mineral
Dalmation Stone (Dalmation Jasper)
Peralkaline rock (primarily Feldspar and Quartz with Arfvedsonite spots)
igneous
Biotite (Black Mica)
Biotite (K(Mg,Fe++)3AlSi3O10(OH,F)2)
mineral
Sandstone (Quartzose)
Arenite (Siliciclastic sedimentary rock)
sedimentary
Serpentine Jade (New Jade/Olive Jade)
Serpentinite (a rock composed primarily of serpentine minerals) / Mg3Si2O5(OH)4 for Antigorite and Lizardite
Mineral
Serpentinite
Serpentinite (composed primarily of Serpentine group minerals: (Mg,Fe)3Si2O5(OH)4)
metamorphic
Granite Cobble
Plutonic Granite
igneous
Geode (Unopened)
Silicon dioxide with various inclusions (SiO2)
sedimentary
Prehnite
Prehnite (Ca2Al(AlSi3O10)(OH)2)
mineral
Emerald
Beryl (Be3Al2(SiO3)6) with chromium/vanadium impurities
mineral
Amazonite
Microcline (KAlSi3O8) with lead impurities
mineral
Peridot
Olivine (Mg, Fe)2SiO4
mineral
Citrine Quartz
Silicon Dioxide (SiO2)
mineral
Precious Opal in Matrix
Hydrated Silica (SiO2·nH2O)
mineral
Citrine
Crystalline Quartz (SiO2) with iron impurities
mineral
Red Coral
Corallium rubrum (Calcium Carbonate, CaCO3 with Carotenoid pigments)
Mineraloid (Organic Gemstone)
Black Opal
Hydrated Silica (SiO2·nH2O)
Mineraloid
Staurolite (Fairy Stone)
Staurolite (formula: Fe2+2Al9Si4O23(OH))
metamorphic
Okenite (in Zeolite matrix)
Okenite (CaSi2O5 · 2H2O)
mineral
Red Sandstone
Arenite (with Iron Oxide / Hematite staining)
sedimentary