Human Skin (Epidermis/Dermis)
Integumentary tissue (High content of hydroxyapatite in bones, though the surface is biological)
Mineral-like biological tissue
Category
Mineralogical Specimen
Browse mineralogical specimen specimens identified by the Rock Identifier community.
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Milky Quartz Vein in Host Rock
Silicon Dioxide (SiO2)
mineral
Quartz (or Chalcedony) Specimen
Silicon Dioxide (SiO2)
mineral
Fossil Shark Tooth
Carcharadon sp. (likely Carcharodon carcharias or similar Lamniformes)
fossil
Note: No specimen visible
N/A
Dyed Tumbled Quartz (Dragon's Vein Agate/Quartz)
Silicon Dioxide (SiO2) with artificial dye
mineral
Dyed Agate (Tumbled)
Silicon Dioxide (Chalcedony variety, artificially dyed)
gemstone
Weathered basaltic volcanic rock
Likely vesicular basalt or basaltic-andesite; chiefly plagioclase, pyroxene, and iron-bearing minerals
igneous
Fossilized Oyster in Flint
Gryphaea or Exogyra embedded in SiO2 (Flint/Chert)
fossil
Brachiopod Fossil in Limestone
Phylum Brachiopoda embedded in sedimentary rock
fossil
Fossilized Bone Chunk
Permineralized Vertebrate Bone (indeterminant)
fossil
Clear Quartz
SiO2 (Silicon Dioxide)
gemstone
Quartz Geode with Calcite
Silicon Dioxide (SiO2) and Calcium Carbonate (CaCO3)
Mineral/Geode
Gold in Quartz Matrix
Native Gold (Au) with Quartz (SiO2)
mineral
Chert
Microcrystalline Quartz (SiO2)
sedimentary
Cobalt Blue Glass / Cullet Glass
Silicon dioxide (Amorphous man-made glass)
mineral
Quartz Vein in Schist
Quartz (SiO2) in Mica Schist
metamorphic
Shale with Trace Fossils
Fissile mudrock (Shale)
sedimentary
Granite with Mafic Xenolith
Intrusive Igneous Rock containing a Xenolith
igneous
Chert (Chalcedony)
Cryptocrystalline Quartz (SiO2)
sedimentary
Note: Item is not a geological specimen
n/a
none
Botryoidal Agate
Silicon Dioxide (SiO2)
mineral
Quartz (Field Specimen)
Silicon Dioxide (SiO2)
mineral
Lemon (Mock specimen mimicking Citrine/Sulfur)
Citrus x limon
Organic (Biological specimen)
Chert (with potential fossil inclusion)
Microcrystalline Quartz (SiO2)
sedimentary
Ferruginous Quartz
Silicon Dioxide (SiO2) with iron oxide inclusions (Limonite/Hematite)
mineral
Cullet Glass (Slag)
Amorphous Silicon Dioxide (Man-made)
Mineraloid
Raw black tourmaline (likely schorl)
Schorl, sodium–iron tourmaline; approximately NaFe²⁺₃Al₆(BO₃)₃Si₆O₁₈(OH)₄
mineral
Chert (Arrowhead/Scraper Preform)
Silicon dioxide (SiO2)
sedimentary
Quartz (Citrine or Iron-Stained variety)
Silicon Dioxide (SiO2)
mineral
Weathered quartz-rich sandstone or granitic rock
Indeterminate; likely iron-stained quartz sandstone, possibly weathered granite
sedimentary
Unable to identify - Image contains non-geological items
N/A
Muscovite Schist
Metamorphic rock primarily composed of quartz and muscovite mica
metamorphic
Blue Obsidian
Volcanic Glass (SiO2 with inclusions)
igneous
Quartz Vein in River Siltstone
Crystalline Quartz (SiO2) in Siliclastic Matrix
sedimentary
Banded Gneiss
Metamorphic Gneiss (High-grade regional metamorphism specimen)
metamorphic
Small rounded pebble, likely quartz-rich stone
Indeterminate from photograph; possibly microcrystalline quartz (SiO₂) or a weathered silicate pebble
mineral
Diamond
Carbon (C)
mineral
Pyrite with Quartz
Iron Sulfide (FeS2) with Silicon Dioxide (SiO2)
mineral
Jasper
Silicon Dioxide (Microcrystalline Quartz), SiO2
sedimentary
Quartz (Milky/Clear variety)
Silicon Dioxide (SiO2)
mineral
Opal
Hydrated Silica (SiO2·nH2O)
mineraloid