Gneiss (with Quartz and Mica)
Gneiss
metamorphic
Category
The Purple Specimen Is A Mineral (Amethyst); The White Specimen Is A Sedimentary Rock (Limestone Or Marble).
Browse the purple specimen is a mineral (amethyst); the white specimen is a sedimentary rock (limestone or marble). specimens identified by the Rock Identifier community.
Chalcedony (Agate/Carnelian type)
Silicon Dioxide (SiO2)
mineral
Quartzite
Quartzite (SiO2)
metamorphic
Moldavite
Tektite (Impact Glass), ~80% SiO2 + Al2O3
tektite
Milky Quartz in Matrix
Silicon Dioxide (SiO2)
mineral
River Rocks (Basalt and Sedimentary Stones)
Mafic Igneous Rock (Basalt) and Clastic Sedimentary Rock
igneous and sedimentary
Prehnite
Prehnite Ca2Al2Si3O10(OH)2
mineral
Bull Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
mineral
Porphyry
Porphyritic Rhyolite or Andesite
igneous
Banded Agate (specifically Eye Agate / Chalcedony)
Agate (Cryptocrystalline variety of Quartz, SiO2)
mineral
Drill Core Samples (Varied Lithology)
Multi-lithological core samples (containing potential granite, marble, and phyllite/schist sequence)
igneous, sedimentary, and metamorphic
Quartz
Quartz (SiO2)
Mineral
Lapis Lazuli (Tumbled Stone)
Na6Ca2(Al6Si6O24)(SO4,S,Cl)2 (predominantly Lazurite)
metamorphic
Conglomerate
Conglomerate (clastic sedimentary rock)
sedimentary
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Honey Calcite (Yellow Calcite)
Calcium Carbonate (CaCO3)
mineral
Quartzite with Quartz Vein
Quartzite (primarily SiO2)
metamorphic
Granite (River Pebble)
Phaneritic intrusive igneous rock (Felsic)
igneous
Granite Pebble
Granite (composition of Quartz, Alkali Feldspar, and Plagioclase)
igneous
Banded Agate
Chalcedony (cryptocrystalline variety of Quartz), SiO2
mineral
Ironstone Concretion (Moqui Marble)
Iron-oxide Concretion (Hydrated ferric oxide, Fe2O3·nH2O)
sedimentary
Limestone
Calcium carbonate ( преимущественно CaCO3)
sedimentary
Septarian Nodule
Septarian Concretion (CaCO3 with Siderite/Calcite/Aragonite)
sedimentary
Quartz Geode
Silicon Dioxide (SiO2)
mineral
Sandstone (likely Siltstone variety)
Arenite / Siltstone (primary mineral SiO2)
sedimentary
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Pyrite in Quartz
Iron Sulfide (FeS2) in Silicon Dioxide (SiO2)
mineral
Quartzite River Pebble
Quartzite (primarily SiO2)
metamorphic
Banded Gneiss
Gneiss (High-grade Regional Metamorphic Rock)
metamorphic
Quartzite
Quartzite (SiO2)
metamorphic
Gneiss Pebble
Gneiss
metamorphic
Desert Rose (Baryte/Gypsum Rosette)
Baryte (BaSO4) or Gypsum (CaSO4·2H2O)
mineral
Turquoise
CuAl6(PO4)4(OH)8·4H2O (Hydrous phosphate of copper and aluminium)
mineral
Rough Tanzanite
Zoisite (Ca2Al3(SiO4)3(OH))
mineral
Fluorite (Rainbow Fluorite)
Calcium Fluoride (CaF2)
mineral
Smoky Quartz
Silicon Dioxide (SiO2) with aluminum impurities
mineral
Rose Quartz
Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese
mineral
Muscovite Schist with Quartz
KAl2(AlSi3O10)(OH)2 in Schistose matrix
metamorphic
Amber-bearing Coal/Sedimentary Rock
Bituminous coal or carbonaceous siltstone with Fossilized Tree Resin (C10H16O)
sedimentary
Quartzite (with possible Calcite/Limestone weathering)
Quartzite (primarily SiO2)
metamorphic
Limestone with Calcite Veins
Sedimentary Calcium Carbonate (CaCO3)
sedimentary
Chert (Jasper/Agate variety)
Microcrystalline Quartz (SiO2)
sedimentary