Limonite
FeO(OH)·nH2O (Hydrated iron oxide)
mineral
Category
Man Made Material, Not A Natural Rock Or Mineral Specimen
Browse man made material, not a natural rock or mineral specimen specimens identified by the Rock Identifier community.
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Turquoise
CuAl6(PO4)4(OH)8·4H2O (Hydrous phosphate of copper and aluminium)
mineral
Blue Dyed Agate Geode (Slice)
Silicon Dioxide (SiO2) - Chalcedony / Quartz
mineral
Moonstone (specifically Rainbow Moonstone / White Labradorite)
White Labradorite (Feldspar Group: (Na,Ca)(Al,Si)4O8)
mineral
Tumbled azurite–malachite or blue jasper (tentative)
Likely azurite-bearing copper mineral aggregate; composition commonly Cu₃(CO₃)₂(OH)₂ with associated malachite Cu₂CO₃(OH)₂
mineral
Sandstone (Quartz-rich)
Clastic sedimentary rock (SiO2 primary)
sedimentary
Obsidian
Volcanic glass (silica-rich rhyolitic melt; primarily SiO₂)
igneous
Clear Quartz
Silicon Dioxide (SiO2)
mineral
Ferruginous Siltstone
Siltstone with Magnetite/Hematite bands
sedimentary
Chert (Jasper type)
Microcrystalline Quartz (SiO2)
sedimentary
Black Obsidian
Obsidian (Volcanic Glass, SiO2 + impurities)
igneous
Likely dark green-gray metamorphic pebble
Indeterminate; possibly chlorite schist, serpentinite, or amphibolite
metamorphic
Rough Diamond
Diamond (Native Carbon, C)
mineral
Quartz (likely Jasper or Chert variety)
Quartz (SiO₂)
Mineral
Waterworn Pebble / Quartzite
Metamorphic/Sedimentary rock fragment
sedimentary
Carnelian
Carnelian (Silicon Dioxide - SiO2)
mineral
Quartz geode or drusy quartz cluster
Quartz (silicon dioxide, SiO₂), likely microcrystalline quartz lining a cavity
mineral
Druzy quartz geode
Microcrystalline quartz (SiO₂), commonly lining a volcanic geode cavity
mineral
Flowerstone
Porphyritic Basalt or Porphyritic Andesite
igneous
Polished pink chalcedony (likely pink agate/geode)
Microcrystalline quartz, SiO₂; chalcedony with iron-bearing inclusions and possible druzy quartz
mineral
Red Jasper with Quartz
Microcrystalline Quartz (SiO2)
sedimentary
Tumbled jasper, likely red/brown jasper
Microcrystalline quartz (chalcedony), SiO₂, colored by iron oxides
metamorphic
Jasper
Silicon dioxide (SiO2)
sedimentary
Sandstone (Greywacke/Siltstone variant)
Arenite / Wacke (SiO2 with diverse mineral inclusions)
sedimentary
Diorite (Salt and Pepper Rock)
Diorite
igneous
Clear quartz sphere
Quartz (silicon dioxide, SiO₂), likely rock crystal or low-grade milky quartz
mineral
Sandstone (with potential trace fossils)
Clastic sedimentary rock (primarily SiO2)
sedimentary
Yellow-green jasper or serpentine-rich rock
Likely microcrystalline quartz (SiO₂) with iron-bearing and/or serpentine minerals; exact identification requires testing
mineral
Vesicular Basalt (Scoria)
Basalt (Extrusive Igneous Rock)
igneous
Goldstone and Aura Quartz
Cuprous Glass (Goldstone) and Titanium-coated SiO2 (Aura Quartz)
Mineral/Glass Specimen
Pearl
Calcium Carbonate (mostly Aragonite), CaCO3 (with conchiolin)
mineral
Granite (likely weathered quartz-bearing granite)
Granite; primarily quartz, feldspar, and mica/amphibole
igneous
Shale (sub-type: Carbonaceous Shale)
Lutaceous Sedimentary Rock
sedimentary
Milky Quartz with Iron Inclusions
Silicon Dioxide (SiO2)
mineral
Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Diamond
Carbon (C)
mineral
Citrine
Silicon Dioxide (SiO2) with trace Iron
mineral
Red Sandstone
Arenite (predominantly SiO2 with Fe2O3 staining)
sedimentary
Ferruginous Slag (Iron Smelting Byproduct)
Fused Silicate Scoria (Amorphous mixture of FeO, SiO2, and CaO)
Antropogenic Glass / Mineraloid
Layered shale and sandstone gorge
Shale and thin-bedded sandstone, likely Devonian or older sedimentary strata
sedimentary
Sandstone (Quartzose Sandstone)
Clastic sedimentary rock (primarily SiO2)
sedimentary
Granitoid (Granite/Granodiorite)
Plutonic igneous rock (variable composition, primarily SiO2)
igneous