Anthracite coal
Anthracite; predominantly carbon (C), with minor mineral impurities
Category
Browse mineral (refined metal) specimens identified by the Rock Identifier community.
Anthracite coal
Anthracite; predominantly carbon (C), with minor mineral impurities
Green Aventurine
Silicon Dioxide (SiO2) with Fuchsite inclusions
Anthropogenic Heat Source (Electronic/Industrial Interface)
Thermal IR emission (Electronic infrastructure)
Mica Schist
Mica Schist (Composition typically includes Muscovite KAl2(AlSi3O10)(OH)2 and Quartz SiO2)
Banded Iron Formation
Banded Iron Formation (BIF)
Lepidolite
K(Li,Al)3(Al,Si)4O10(F,OH)2 (Lithium-bearing phyllosilicate)
Mica Schist / Granite
Mica Schist (Silicate metamorphic rock)
Cullet Glass (Industrial Slag Glass)
Amorphous Silica (SiO2) with metallic oxide impurities
Sunstone
Plagioclase Feldspar (specifically Oligoclase variety containing hematite or goethite inclusions)", composition: (Ca,Na)(Al,Si)2Si2O8
Hematite Beads
Hematite (Fe2O3)
Pyrite
Pyrite (Iron Disulfide), FeS2
Mica Schist
Schist (muscovite/biotite rich regional metamorphic rock)
Basalt
Basalt
Fancy Jasper (Butterfly Carving)
Silicon Dioxide (SiO2) with iron and manganese inclusions
Fossil-bearing ironstone or weathered concretion
Indeterminate; likely ferruginous sandstone/concretion containing a partial fossil impression
Banded Iron Formation (BIF) / Banded Sandstone Nodule
Hematite-rich Sandstone / Ferruginous Chert
Fluorite
Fluorite (Calcium Fluoride, CaF2)
Fluorite
Fluorite (Calcium Fluoride, CaF2)
Gneiss with Iron Staining and Sulfide Mineralization
Metamorphic Gneiss / Amphibolite with Iron/Sulfide Oxidation
Lapis Lazuli
Lazurite-dominant rock, (Na,Ca)8(AlSiO4)6(SO4,S,Cl)2
Rutilated Quartz
SiO2 with TiO2 inclusions
Basalt
Mafic Igneous Rock (composed primarily of pyroxene and calcium-rich plagioclase)
Banded Iron Formation
Banded Iron Formation (BIF)
Green Aventurine (Green Quartz)
Silicon Dioxide (SiO2) with inclusions of Fuchsite (K(Al,Cr)2(AlSi3O10)(OH)2)
Ironstone Concretion / Goethite-Hematite Geode
Goethite / Hematite Concretion (Fe3O4 / FeO(OH) / Fe2O3)
Pyrite-bearing rock (likely pyrite in a quartz or sulfide-rich matrix)
Pyrite, FeS₂; the gray host may be quartz, carbonate, or another sulfide-bearing rock
Limonite (Iron Ore/Hydrated Iron Oxide)
Limonite (mixture of FeO(OH)·nH₂O minerals, mainly Goethite, FeO(OH) and Lepidocrocite, FeO(OH))
Goethite
Goethite (α-FeO(OH))
Mixed Tumbled Gemstones and River Rocks
Mixed Decorative Stones (predominantly Silicon Dioxide - SiO2 variants)
Ferruginous Slag (Iron Smelting Byproduct)
Fused Silicate Scoria (Amorphous mixture of FeO, SiO2, and CaO)
Scoria (Lava Rock)
Scoria (Vesicular Basaltic Rock)
Quartz (milky variety)
SiO2 (Silicon Dioxide)
Sunstone and Green Aventurine
Sunstone: (Ca,Na)[(Al,Si)2Si2O8] (Plagioclase Feldspar Group); Green Aventurine: SiO2 (Quartz)
Fluorite (often referred to casually as 'Fluorspar' in industrial contexts)
Fluorite (CaF2)
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.
Micaceous Sandstone or Quartzite
Sandstone (lithified quartz grains, often with mica) or Quartzite (metamorphosed sandstone)
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.
Peridot
Olivine (Mg,Fe)2SiO4
Rutilated Quartz (or Tourmalinated Quartz if inclusions are Tourmaline)
Silicon Dioxide (SiO2) with Rutile (TiO2) or Tourmaline inclusions
Aventurine
Aventurine Quartz (SiO2 with inclusions)
Green Aventurine
Silicon Dioxide (SiO2) with Fuchsite inclusions
Schist (Micaceous Schist)
Micaceous schist (Mainly Muscovite/Biotite mixed with Quartz)