Muscovite Mica (Golden/Yellow variety)
KAl2(AlSi3O10)(F,OH)2
mineral
Category
Mineral, Often Found As A Rock
Browse mineral, often found as a rock specimens identified by the Rock Identifier community.
Quartz Pebble
Silicon Dioxide (SiO2)
mineral
River Stone (likely Siltstone or fine-grained Sandstone)
Clastic Sedimentary Rock (Lithic Wacke / Siltstone)
sedimentary
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Ruby in Zoisite (Anyolite)
Corundum var. Ruby in Zoisite (Al2O3 + (Ca2Al3(SiO4)3(OH)))
metamorphic
Yellow Quartz (Chalcedony or Agate)
Silicon Dioxide (SiO2)
mineral
Pyrite on Limestone
Iron Disulfide (FeS2) in Calcium Carbonate (CaCO3) matrix
sedimentary (matrix) / mineral (inclusion)
Sandstone (likely Arkosic)
Clastic Sedimentary Rock (primarily SiO2 with Feldspar)
sedimentary
Chert (Nodule)
Silicon Dioxide (SiO2)
sedimentary
Dalmatian Jasper
Peralkaline rhyolite with Arfvedsonite inclusions
igneous
Agate (Lace Agate Geode Slice)
Silicon Dioxide (SiO2)
mineral
Yellow Jasper
Silicon Dioxide (SiO2) with Goethite/Iron Oxide inclusions
sedimentary
Unakite
Unakite (Metasomatized Granodiorite)
metamorphic
Sandstone (Quartzose Sandstone)
Clastic Sedimentary Rock (primarily SiO2)
sedimentary
Milky Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
mineral
Limonite (Iron Stone Concretion)
Limonite (Hydrous Iron Oxide) - FeO(OH)·nH2O
mineral
Sandstone (Quartzose Sandstone)
Arenite (SiO2 primarily)
sedimentary
Boxwork Quartz / Septarian Jasper
Boxwork (SiO2 with iron oxide inclusions)
metamorphic
Granite (Pink/Red)
Phaneritic Plutonic Felsic Rock (major minerals: Quartz, Orthoclase Feldspar, Plagioclase Feldspar)
igneous
Rose Quartz
Silicon Dioxide (SiO2)
mineral
Aragonite / Calcite Geode
Calcium Carbonate (CaCO3)
mineral
Sandstone
Clastic sedimentary rock (primarily SiO2)
sedimentary
Iron Slag (Industrial Byproduct)
Anthropogenic Vitrification Product/Ferrous Slag
Mineral-like Industrial Smelting Waste
Quartz / Quartzite
Silicon Dioxide (SiO2)
mineral / metamorphic
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
mineral
Unknown Organic Object (likely a berry or fruit)
Not applicable; this is not a geological specimen. If it were a cranberry, its scientific name would be Vaccinium macrocarpon; if a cherry, it would be Prunus avium or Prunus cerasus.
Organic Material (likely a fruit or berry)
Sandstone (likely Arkosic)
Arenite (SiO2 with KAlSi3O8)
sedimentary
Sandstone
Arenite (often composed of Quartz, SiO2)
sedimentary
Brown Sandstone
Arenite (primarily Quartz and Feldspar, with Iron Oxide cement)
sedimentary
Sandstone (with Iron Staining)
Clastic Sedimentary Rock (primarily Quartz with Fe2O3 staining)
sedimentary
Yellow Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Unakite
Unakite (Altered Granite)
metamorphic
Chert (Iron-stained)
Microcrystalline Quartz (SiO2)
sedimentary
Chert with Quartz/Calcite Vein
Microcrystalline Silica (SiO2)
sedimentary
Banded Gneiss
Gneiss (Metamorphic Rock)
metamorphic
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2 with iron oxide inclusions)
metamorphic
Gold Nugget
Native Gold (Au)
mineral
Gold Nugget
Native Gold (Au)
mineral
Sandstone
Clastic Sedimentary Rock (composed mostly of quartz, SiO2)
sedimentary
Sandstone
Arenite (SiO2 based with primary clasts 0.0625 to 2 mm)
sedimentary
Unakite or Epidosite
Epidosite (Mineral composition: Epidote, Feldspar, and Quartz)
metamorphic
Blue Calcite
Calcium Carbonate (CaCO3)
mineral