Pyrite
Iron Disulfide (FeS2)
Category
Browse mineral precipitate (anthropogenic context) specimens identified by the Rock Identifier community.
Pyrite
Iron Disulfide (FeS2)
Yellow Quartz (Citrine Quartz)
Silicon Dioxide (SiO2)
River Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
Banded Calcite (often sold as 'Mexican Onyx' or 'Green Onyx')
Calcite (Calcium Carbonate, CaCO3)
Granodiorite
Granodiorite
Talc
Talc (Mg₃Si₄O₁₀(OH)₂)
Sandstone with Algae Growth
Arenite with Chlorophyta/Lichen
Granite
Felsic Intrusive Igneous Rock (SiO2, Al2O3, K2O, Na2O)
Granite
Phaneritic plutonic rock (Quartz, Feldspar, Mica)
Muscovite Mica
Muscovite (Potassium Aluminum Silicate Hydroxide Fluoride), KAl2(AlSi3O10)(OH,F)2
Sodalite
Sodalite (Na8(Al6Si6O24)Cl2)
Pyrite with Iron Oxides (Fool's Gold in Matrix)
Iron Sulfide (FeS2)
Olivine (Peridot)
Magnesium Iron Silicate (Mg, Fe)2SiO4
Shale (with Iron Oxide staining)
Fissile Mudstone (primarily Quartz and Clay minerals)
Asphalt (Bituminous Concrete)
Composite material (bitumen binder with mineral aggregate)
Pegmatite
Granitic Pegmatite
Serpentine Jade (New Jade/Olive Jade)
Serpentinite (a rock composed primarily of serpentine minerals) / Mg3Si2O5(OH)4 for Antigorite and Lizardite
Mica (Biotite or Phlogopite variety)
Phyllosilicate (complex mineral formula involving K, Mg, Fe, Al, Si, and O)
Labradorite
Labradorite (a calcium-enriched feldspar mineral), (Ca, Na)(Al, Si)4O8
Labradorite (Polished Crystal Point)
Labradorite (a calcium-enriched feldspar mineral), (Ca, Na)(Al, Si)4O8
Quartz (Iron-stained)
Silicon Dioxide (SiO2)
Quartz Pebble
Silicon Dioxide (SiO2)
Nuummite
Nuummite (intergrowth of orthoamphiboles Anthophyllite and Gedrite, (Mg,Fe)7Si8O22(OH)2)
Granite
Intrusive Felsic Igneous Rock
Blue Goldstone
Aventurine Glass (Silicon Dioxide with metal inclusions)
Granodiorite
Granodiorite (calc-alkaline phaneritic igneous rock)
Schist
Mica Schist
Granite
Phaneritic Granocrystalline Igneous Rock
Diorite (River Pebble)
Diorite
Gneiss
Gneissic Metamorphic Rock
Gneiss
Gneiss
Andesite
Intermediate Volcanic Rock (Andesite)
Diabase (Greenstone Pebble)
Diabase or Dolerite
Sandstone Pebble with Iron Staining
Clastic Sedimentary Rock (primarily Quartz with Fe2O3 oxides)
Pink Sapphire
Corundum (Al2O3) with Chromium/Iron/Titanium trace impurities
Granite
Granite (Mainly Quartz SiO2, Alkali Feldspar (K,Na)AlSi3O8, and Plagioclase Feldspar)
Amethyst
Quartz variety; SiO2 (Silicon Dioxide)
Prehnite
Prehnite (Ca2Al2Si3O10(OH)2)
Celestite (Celestine)
Strontium sulfate (SrSO4)
Ironstone Nodules / Siderite Concretion
Siderite (FeCO3) / Ferruginous Septarian Concretion
Granite (Weathered)
Phaneritic Felsic Igneous Rock
Granite
Phaneritic Igneous Rock (Granite)