Peridotite
Ultramafic intrusive igneous rock (composition: (Mg, Fe)2SiO4)
igneous
Category
Industrial Byproduct (Anthropogenic Rock)
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Quartzite
Metamorphic Quartz Sandstone
metamorphic
Bauxite
Alumina-rich rock (consisting of Gibbsite, Boehmite, and Diaspore)
sedimentary
Dumortierite Quartz (Blue Quartz)
Al7BO3(SiO4)3O3 (Aluminum Boro-silicate included in Quartz)
mineral
Clear Quartz (Rock Crystal)
Quartz (Silicon Dioxide - SiO2)
mineral
Chert (often called Flint or Jasper)
Silicon Dioxide (SiO2)
sedimentary
White quartz in dark matrix (likely quartz-bearing breccia or polished composite specimen)
Quartz, SiO₂, in an unidentified dark silicate matrix
mineral
Orbicular jasper (likely ocean jasper)
Silica-rich microcrystalline quartz/chalcedony with iron-oxide and other mineral inclusions; commonly classified as orbicular jasper
mineral
Red Quartzite
Quartzite (SiO2 with iron oxide impurities)
metamorphic
Milky Quartz (with Iron Oxide staining)
Quartz (Silicon Dioxide - SiO2)
mineral
Chert (Quartz Pebble)
Silicon Dioxide (SiO2)
sedimentary
Chert (Nodule)
Microcrystalline or cryptocrystalline Quartz (SiO2)
sedimentary
Quartzite
Quartzite (SiO2 silicon dioxide)
metamorphic
Dark rounded pebble, likely basalt or slag
Probable fine-grained mafic rock; possibly basalt (plagioclase–pyroxene) or industrial iron/steel slag
igneous
Quartz Geode
Silicon Dioxide (SiO2)
mineral
Granite
Phaneritic intrusive igneous rock (Composition: Quartz, Feldspar, Mica)
igneous
Tumbled or naturally etched mica-rich mineral specimen, likely muscovite
Muscovite, KAl₂(AlSi₃O₁₀)(OH)₂; possibly phlogopite mica
mineral
Chert (Jasper variety)
Silicon Dioxide (SiO2)
sedimentary
Rounded gray river pebble, likely fine-grained sandstone or siltstone
Indeterminate clastic sedimentary rock; possibly quartz-rich sandstone or siltstone
sedimentary
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.
Organic Material (likely a fruit or berry)
Quartz geode / chalcedony nodule
Silica, primarily quartz (SiO₂), with microcrystalline chalcedony
mineral
Milky Quartz
Quartz (SiO2) with iron staining
mineral
Milky Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
mineral
Banded Agate
Cryptocrystalline Quartz (SiO2)
mineral
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
mineral
Polished Picasso jasper
Silicified carbonate rock, commonly marketed as Picasso jasper; composition varies and is not a single mineral species
metamorphic
Rose Quartz
Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese
mineral
Granitic Pegmatite
Coarse-grained Granite (KAlSi3O8 + SiO2)
igneous
Cobalt Blue Sea Glass
Amorphous Silica Glass (SiO2 + CoO)
mineraloid / anthropogenic material
Synthetic Zinc/Polycarbonate Composite (Bey-specimen)
Zinc Alloy (Zamak 3) with Polycarbonate (C15H16O2)n Overlay
Anthropogenic Mineral Mimic
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Pink Quartzite
Quartzite (SiO2 with iron oxide inclusions)
metamorphic
Quartzite
Quartzite (SiO2)
metamorphic
Quartzite
Quartzite (SiO2)
metamorphic
Quartzite
Quartzite (SiO2)
metamorphic
Quartzite
Quartzite (primarily SiO2)
metamorphic
Granite Pebble
Felsic Plutonic Rock (primarily Quartz, Feldspar, and Mica)
igneous
Schist
Mica Schist (primarily Muscovite and Quartz)
metamorphic
Quartzite Pebble
Metamorphosed Quartz Sandstone (SiO2)
metamorphic
Quartzite
Quartzite (SiO2 silicon dioxide)
metamorphic
Pegmatite (Granitic Pegmatite with Quartz, Feldspar, and Mica)
Granitic Pegmatite
igneous
Banded Chert in Matrix
Microcrystalline Quartz (SiO2)
sedimentary