Industrial Byproduct (Anthropogenic Rock)

Quartzite

Silica (SiO2)

Iolite-bearing Gneiss (Cordierite)

Cordierite (Mg2Al4Si5O18) in Gneiss matrix

Chert (Yellow Jasper variant)

Microcrystalline Quartz (SiO2)

Schorl (Black Tourmaline) in Pegmatite

Sodium Iron Aluminum Borosilicate (NaFe3Al6(BO3)3Si6O18(OH)4)

Corundum (Sapphire in Host Rock)

Corundum (Aluminum Oxide, Al2O3)

Quartzite

Quartzite (Primary mineral: SiO2)

Ironstone (likely Ferruginous Siltstone/Sandstone)

Ferruginous sedimentary rock (FeOx-rich clastic)

Milky Quartz (Gold-bearing Prospecting Specimen)

Silicon Dioxide (SiO2)

Red Jasper

Jasper (Silicon Dioxide, SiO2 with Fe2O3 inclusions)

Milky Quartz Pebble

Quartz (Silicon Dioxide, SiO2)

Quartzite (or Quartz Rich Conglomerate)

Quartzite (SiO2 silicon dioxide)

Jasper (Red Jasper)

Silicon Dioxide (SiO₂)

Granite (Core Sample)

Phaneritic Felsic Igneous Rock (Granite)

Quartz (likely Milky Quartz)

Quartz (SiO₂ - Silicon Dioxide)

Clear Quartz (Rock Crystal)

Quartz (Silicon Dioxide, SiO2)

Quartz Pebble

Silicon Dioxide (SiO2)

Granite

Granite

Anthracite Coal

Anthracite (Carbon-based metamorphic rock)

Anthracite Coal

Anthracite (Carbon-rich metamorphic rock)

Gneiss

Gneiss (High-grade regional metamorphic rock)

Mica Schist

Crystalline Schist (often primarily Muscovite or Biotite sheet silicates)

Basalt Arrowhead (worked stone)

Aphanitic mafic volcanic rock (Basalt)

Mica Schist with Pyrite

Muscovite/Biotite Schist with Iron Sulfide (FeS2)

Quartzite

Quartzite (primarily SiO2)

Banded Flint (Polished Stripe Flint)

Silicon Dioxide (SiO2) - variety of Chert

Quartzite

Quartzite (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Olivine-bearing Basalt / Scoria

Mafic Igneous Rock (primarily (Mg, Fe)2SiO4)

Granitic Pegmatite

Granite Pegmatite (principally KAlSi3O8, SiO2, and KAl2(AlSi3O10)(OH)2)

Milky Quartz with Mineral Inclusions

Quartz (Silicon Dioxide, SiO2)

Agate and Amethyst (Quartz variants)

Silicon Dioxide (SiO2) - Microcrystalline Quartz and Crystalline Quartz

Sandstone Beach Pebble

Clastic Sedimentary Rock (primarily Quartz with Iron Oxide coating)

Pink Quartzite

Quartzite (primarily SiO2 with trace impurities of iron oxides)

Chert (specifically Flint or Gray Chalcedony)

Microcrystalline Quartz (SiO2)

Black Tourmaline

Schorl (Na(Fe²⁺)₃Al₆(BO₃)₃Si₆O₁₈(OH)₄)

Rose Quartz

Silicon dioxide (SiO2) with trace amounts of titanium, iron, or manganese

Orange Quartzite (River Pebble)

Quartzite (primarily SiO2)

Ferruginous Sandstone (River Pebble)

Clastic Sedimentary Rock (primarily SiO2 with Fe2O3 cement)

Diamond (as set in a metal alloy ring)

Diamond (Pure Carbon, C)

Banded Sandstone (Quartzite-rich)

Clastic Sedimentary Rock (SiO2 with Iron Oxide impurities)

Blue Sapphire

Corundum (Al2O3)

Banded Agate (specifically Sardonyx)

Silicon Dioxide (SiO2) - variety of Chalcedony/Quartz