Pyrite Geode
Iron Disulfide (FeS2)
Category
Browse not a rock or mineral (anthropogenic material) specimens identified by the Rock Identifier community.
Pyrite Geode
Iron Disulfide (FeS2)
Greywacke (likely)
Greywacke (a type of sandstone)
Milky Quartz
Quartz (Silicon Dioxide - SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Silver (Morgan Dollar)
Native Silver (Ag) - 90% Silver, 10% Copper alloy
Amazonite
K(AlSi3O8), Microcline (potassium feldspar)
Slate
Slate (a fine-grained, foliated metamorphic rock). Mineral composition: Primarily composed of mica minerals (muscovite, chlorite, sericite) and quartz, with minor amounts of hematite, pyrite, and other accessory minerals.
Clear Quartz (or Rock Crystal)
Quartz (SiO₂ - Silicon Dioxide)
Epidote in Matrix
Epidote; Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)
Wishing Stone (Basalt or Siltstone with Quartz/Calcite Vein)
Basalt (SiO2+MgO+FeO) or Siltstone with a Quartz (SiO2) or Calcite (CaCO3) vein
Calcite
Calcite (Calcium Carbonate, CaCO3)
Shungite
Non-crystalline carbon (allotrope of carbon)
Quartz Pebble
Silicon Dioxide (SiO2)
Quartz (likely milky quartz or a stained variety)
Silicon Dioxide (SiO₂)
Agate
Agate (a variety of Chalcedony, SiO2)
Chert (Field Stone)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (variously identified as Flint)
Microcrystalline Quartz (SiO2)
Diamond
Native Carbon (C)
Pumice
Pumice (volcanic glass with vesicular texture)
Chert / Flint
Silicon Dioxide (SiO2)
Red Sandstone
Arenite (Ferruginous Sandstone)
Shale or Slaty Mudstone
Argillaceous sedimentary rock
Kaolinite (Chalky Clay)
Kaolinite (Al2Si2O5(OH)4)
Quartz (chalcedony variety) or Limestone with Quartz Veins
SiO2 (for Quartz/Chalcedony); CaCO3 (for Limestone)
Chalcedony (Agate Pebble)
Silicon Dioxide (SiO2)
Shale (possibly)
Shale (fine-grained clastic sedimentary rock)
Sandstone with Secondary Mineral Encrustation
Arenite with Silica/Calcite deposits (SiO2 or CaCO3)
Stichtite in Serpentine (Atlantasite)
Mg6Cr2CO3(OH)16·4H2O in Mg3Si2O5(OH)4
Brecciated Jasper
Silicon Dioxide (SiO2) with Hematite impurities
Red Sandstone
Sandstone (principally Quartz with Iron Oxide coating)
Quartz (pebble)
Quartz (SiO₂)
Diamond
Diamond (pure Carbon, C)
Unable to identify - Image contains non-geological items
Libyan Desert Glass
Impactite (vitreous silica), SiO2
Aragonite Star Cluster
Aragonite (Calcium Carbonate, CaCO3)
Gypsum (Wallboard/Drywall)
Calcium Sulfate Dihydrate (CaSO4·2H2O)
Limonite (Iron Ore)
Limonite (Hydrated Iron Oxide, FeO(OH)·nH2O)
Coquina / Fossiliferous Limestone
Calcite-rich Bioclastic Sedimentary Rock (CaCO3)
Sandstone
Arenite (general term for sandstone)
Petrified Wood
Silicified Wood (primarily SiO2)
Bauxite Ore
Hydrated aluminum oxides (e.g., Gibbsite Al(OH)3, Boehmite ̲̲̲̲AlOOH, Diaspore ̲̲̲̲AlOOH)