Iron-stained quartz vein in altered host rock
Quartz (SiO₂) with iron oxides/hydroxides, likely hematite and goethite; host rock uncertain from the image
metamorphic
Category
Mineral_rock
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Rounded pale quartz-rich pebble
Likely milky quartz or quartzite (SiO₂); exact identification is uncertain from the photograph
mineral
Pyrite (Fool's Gold) in Matrix
Iron Disulfide (FeS2)
mineral
Septarian Nodule
Septarian Concretion (Calcium Carbonate/Aragonite/Calcite)
sedimentary
Rhodochrosite
Manganese carbonate (MnCO3)
mineral
Weathered copper-bearing volcanic rock (likely altered basalt/andesite)
Hydrothermally altered basalt or andesite; green coloration may reflect chlorite, epidote, or copper minerals such as chrysocolla
igneous
Granite with Epidote
Granite, containing quartz, feldspar, and epidote
Igneous
Bauxite
Bauxite (Mixture of Hydrous Aluminum Oxides)
sedimentary
Quartz-rich Diorite
Diorite (Phaneritic intermediate igneous rock)
igneous
Granite fragment
Granite (Felsic intrusive igneous rock)
igneous
Gneiss
Gneiss (High-grade metamorphic rock)
metamorphic
Prehnite
Prehnite (Ca2Al(AlSi3O10)(OH)2)
mineral
Limonite or Ironstone Nodule
Hydrated iron oxide-hydroxide (FeO(OH)·nH2O)
mineral
Vesicular basalt (lava rock)
Vesicular basalt, composed mainly of plagioclase, pyroxene, and often olivine
igneous
Quartz (Druzy or Chalcedony variant)
Silicon Dioxide (SiO2)
mineral
Limonite Concretion
Limonite (Hydrated iron oxide) FeO(OH)·nH2O
sedimentary
Blue apatite (likely rough/tumbled specimen)
Apatite group, commonly fluorapatite — Ca5(PO4)3F
mineral
Fluorite
Calcium Fluoride (CaF2)
mineral
Blue Apatite
Fluorapatite (Ca5(PO4)3F)
mineral
Prehnite
Prehnite (Ca2Al(AlSi3O10)(OH)2)
mineral
Granite-like rock
Coarse-grained felsic intrusive rock, likely granite or granodiorite
igneous
Dark basaltic rock, possibly scoriaceous basalt
Basalt; predominantly plagioclase and pyroxene, with possible olivine and iron oxides
igneous
Fossil Shark Tooth
Odontaspididae (Sand Tiger Shark family)
fossil
Quartz with Sulfide Inclusions
Silicon Dioxide (SiO2) with metallic mineral inclusions
mineral
Quartz Geode
Silicon Dioxide (SiO2)
mineral
Sandstone (likely Arkose or Lithic)
Clastic sedimentary rock (SiO2 + impurities)
sedimentary
Sandstone Pebble
Arenite (Sandstone)
sedimentary
Gravel and Pebbles
Unconsolidated rock fragments / detrital sediment
sedimentary
Granodiorite
Granodiorite (Intermediate intrusive igneous rock)
igneous
Sandstone (Ferruginous)
Arenite (primarily SiO2 with Fe2O3 staining)
sedimentary
Turquoise
Hydrated phosphate of copper and aluminium (CuAl6(PO4)4(OH)8·4H2O)
mineral
Granite
Felsic intrusive igneous rock
igneous
Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Pyrite
Iron Disulfide (FeS2)
mineral
Fluorite
Calcium fluoride (CaF2)
mineral
Turquoise
CuAl6(PO4)4(OH)8"""""""""" """""""""" """""""""" """""""""" """""""""" """""""""" """""""""" """""""""" """""""""" """""""""" """""""""" """""""""" """""""""" """""""""" """""""""" """""""""" """""""""" """""""""" """""""""" """""""""" • 4H2O (Hydrated copper and aluminum phosphate)
mineral
Milky quartz (quartz-rich rock fragment)
Quartz, silicon dioxide (SiO₂)
mineral
Banded Sandstone (Beach Pebble)
Quartz Arenite Sandstone
sedimentary
Vesicular basalt pebble
Basalt, a mafic volcanic rock composed mainly of plagioclase feldspar, pyroxene, and often olivine
igneous
Gneiss
Gneiss
metamorphic
Granite with Mafic Xenolith
Intrusive Igneous Rock (Felsic to Intermediate)
igneous
Tumbled jasper (likely picture/brecciated jasper)
Microcrystalline quartz (chalcedony), SiO₂, colored by iron oxides
mineral