Mineral, Possibly Rock Fragment Containing A Mineral

Mixed collection of Quartz varieties, Chalcedony, and metamorphic pebbles

Mixed gemstones (primarily Silicon Dioxide - SiO2)

Amygdaloidal Basalt

Amygdaloidal Basalt (Host rock) with Quartz or Calcite amygdules

Vesicular Basalt (Lava Rock)

Aphanitic Mafic Igneous Rock

Fulgurite

Fulgurite (Lechatelierite), amorphous SiO2

Asphalt (Bituminous Concrete)

Bituminous Concrete / Pavement

Basalt with Magnetite inclusions

Basalt (Mafic silicate rock) potentially containing Magnetite (Fe3O4)

Fossilized Megalodon Tooth Fragment

Otodus megalodon (Carcharocles megalodon fossil)

Metal Chain (Likely Steel or a Steel Alloy)

Steel (primarily iron and carbon); specific alloy unknown

Fossiliferous Limestone

Biogenic Calcium Carbonate (CaCO3)

Oolitic Limestone (Egg Stone)

Oolite (Chemical sedimentary rock, primarily CaCO3)

Sandstone (Quartzose Sandstone Pebble)

Arenite (primarily SiO2)

Granitic Gneiss

Gneiss (Polymetamorphic Granitic Gneiss)

Milky Quartz

Silicon Dioxide (SiO2)

Turquoise

Hydrated phosphate of copper and aluminium [CuAl6(PO4)4(OH)8·4H2O]

Amethyst Geode Cathedral

Amethyst (Silicon Dioxide - SiO2 with Iron impurities)

Chert (specifically a fragment with Desert Varnish)

Microcrystalline quartz (SiO2)

Moss Agate

Silicon Dioxide (SiO2) with inclusions of Manganese or Iron oxide

Granite

Granite (Felsic Plutonic Rock)

Sandstone (Cross-bedded Drill Core)

Clastic Sedimentary Rock (primarily SiO2)

Sandstone (Weathered Cobble)

Clastic Sedimentary Rock (primarily SiO2)

Gneiss

Gneiss

Fossiliferous Limestone

Calcareous biomicrite / Calcium Carbonate (CaCO3)

Granitic Pegmatite

Coarse-grained Igneous Rock (Granitic composition: KAlSi3O8, SiO2)

Granite Pebble

Felsic Intrusive Igneous Rock (composed of Quartz, Feldspar, and Mica)

Granite (specifically Pink or Alkali Feldspar Granite)

Felsic Plutonic Rock (primarily SiO2 with KAlSi3O8)

Moldavite

Tektite (Impact Glass), ~80% SiO2 + Al2O3

Milky Quartz

Silicon Dioxide (SiO2)

Gold Nugget (Placer Gold)

Native Gold (Au)

Rose Quartz

Silicon Dioxide (SiO2)

Green Quartzite (Aventurine-like)

Quartzite (primarily SiO2 with chromium-rich mica or chlorite inclusions)

Sandstone

Sandstone (composed primarily of sand-sized minerals or rock grains)

Quartz (Smoky Quartz variant)

Silicon Dioxide (SiO2)

K2 Jasper (K2 Granite)

Azurite in Granite (Al2Cu3(CO3)2(OH)2 in NaAlSi3O8)

Schist

Schist (various mineral compositions)

Gowganda Tillite (Puddingstone)

Glacial Diamictite (Gowganda Formation)

Tree Agate

Dendritic Agate (Silicon Dioxide, SiO2)

Sandstone

Arenite (primarily SiO2)

Sandstone

Arenite (primarily SiO2 - Silicon Dioxide)

Sandstone

Arenite (composed primarily of SiO2)

Fossiliferous Limestone

Biogenic Limestone (Calcium Carbonate, CaCO3)

Agate (Thunderegg segment)

Silicon dioxide (SiO2) - Microcrystalline Quartz/Chalcedony

Gneiss

Gneiss (High-grade Metamorphic Rock)