Dark mafic rock, likely basalt or amphibolite
Probable basalt (plagioclase feldspar + pyroxene ± olivine); definitive identification requires a fresh surface or thin section
igneous
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Igneous And Metamorphic Derivative (Weathered)
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Biotite mica schist (probable)
Schist dominated by biotite mica; commonly quartz–feldspar–biotite
metamorphic
Pyrite-bearing quartz vein rock
Pyrite (FeS₂) with quartz (SiO₂), likely in a schistose or altered host rock
mineral
Milky quartz pebble
Quartz (silicon dioxide, SiO₂), chalcedonic or massive variety
mineral
Raw quartz fragment
Quartz (SiO₂), likely milky or included quartz
mineral
Unakite
Altered Granite (Epidotized Granite)
metamorphic
Magnetite (Lodestone variety)
Magnetite (Fe3O4)
mineral
Phyllite (possibly low-grade greenish slate)
Foliated metamorphic rock composed mainly of very fine-grained quartz, mica, and chlorite; approximate composition varies and has no single fixed chemical formula
metamorphic
Milky quartz (rough quartz crystal)
Quartz, silicon dioxide (SiO₂)
mineral
Tumbled white quartz or quartzite pebble
Quartz (SiO₂), possibly massive quartzite
mineral
Hematite
Iron(III) oxide (Fe2O3)
mineral
Magnetite
Magnetite (Fe3O4)
Mineral
Milky quartz fragment
Quartz (silicon dioxide, SiO₂)
mineral
Milky quartz fragment
Quartz (silicon dioxide, SiO₂)
mineral
Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
mineral
Quartz with Mica (likely Muscovite)
Silicon Dioxide (SiO2) with Potassium Aluminum Silicate Hydroxide Fluoride
igneous/metamorphic
Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Quartz Pebble
Silicon Dioxide (SiO2)
sedimentary
Tumbled quartz crystal (probable milky/clear quartz)
Quartz, silicon dioxide (SiO₂)
mineral
Tumbled quartz pebble
Quartz (silicon dioxide, SiO₂)
mineral
Tumbled quartz fragments, likely rose quartz
Quartz (silicon dioxide, SiO₂), possibly iron- or titanium-tinted rose quartz
mineral
Likely tumbled quartz or calcite fragment
Probably quartz (SiO₂) or calcite (CaCO₃)
mineral
Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Yellow Quartz (Citrine or Iron-stained Quartz)
Silicon Dioxide (SiO2)
mineral
Pyrite
Iron Sulfide (FeS2)
mineral
Peacock Ore
Bornite (Cu5FeS4)
mineral
Fossil shark tooth
Likely fossilized shark tooth, possibly Carcharhinus or Otodus species
fossil
Citrine Quartz
Silicon Dioxide (SiO2) with iron impurities
mineral
Rounded quartz-rich pebble, possibly granite or gneiss
Indeterminate granitoid; likely quartz–feldspar–biotite aggregate
igneous
Milky quartz
Quartz, silicon dioxide (SiO₂)
mineral
Nephrite Jade
Nephrite (Ca2(Mg, Fe)5Si8O22(OH)2)
metamorphic
Likely basalt
Basalt; chiefly plagioclase feldspar, pyroxene, and commonly olivine
igneous
Tumbled milky quartz pebble
Quartz, silicon dioxide (SiO₂)
mineral
Quartz vein in weathered host rock
Milky quartz (SiO₂), likely in a feldspathic or carbonate-rich matrix
mineral
Weathered quartz-rich rock, likely granite or gneiss
Indeterminate granitic rock; mainly quartz, feldspar, and mica
igneous
Dark gray crystalline rock, possibly basalt
Basalt (tentative; plagioclase–pyroxene–iron oxide assemblage)
igneous
Magnetite Sand (Black Sand)
Magnetite (Fe3O4)
mineral
Agate
Banded Chalcedony (SiO2 - Silicon Dioxide)
mineral
Mixed Quartz and River Pebbles (Stone Collection)
Mixed assortment containing mainly Silicon Dioxide (SiO2)
igneous, sedimentary, metamorphic, and mineral
Milky quartz
Quartz (silicon dioxide, SiO₂)
mineral
Milky Quartz
Quartz (Silicon Dioxide - SiO2)
mineral
Likely garnet-bearing schist or gneiss
Mica schist/gneiss containing quartz, feldspar, mica, and probable almandine garnet
metamorphic