Rock

Quartz (Vein Quartz)

Silicon Dioxide (SiO2)

Arkosic Sandstone

Arkose

Pumice

Pumiceous rhyolite / Volcanic glass

Red Sandstone

Arenite (primarily Quartz, SiO2, with Iron Oxide cementing agent)

Chalcedony in Matrix

Silicon Dioxide (SiO2)

Limestone

CaCO3 (principally composed of Calcite)

Favosites Fossil (Honeycomb Coral)

Favosites sp. (Extinct genus of tabulate coral)

Granodiorite (or Granite) Pebble

Phaneritic Felsic Igneous Pebble

Gold Ore

Native Gold (Au) in Matrix

Zinc Ore (Sphalerite in Matrix)

Sphalerite (Zn,Fe)S within a carbonate or silicate host rock

Chalcedony in Host Rock

Chalcedony (SiO2)

Porphyritic Basalt (Flowerstone)

Porphyritic Basalt (Mafic volcanic rock)

Chert (Nodular)

Microcrystalline Silica (SiO2)

Fancy Jasper (Ocean Jasper or River Jasper variant)

Silicon Dioxide with inclusions (SiO2)

Quartz (specifically Milky or Clear Quartz)

Silicon Dioxide (SiO2)

Red Quartzite (Tumbled Pebble)

Quartzite (primarily SiO2 with hematite inclusions)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

River Quartz Pitting/Cobble

Silicon Dioxide (SiO2)

Chert (Flint)

Chert (Silicon Dioxide, SiO2)

Carnelian Agate

Silicon Dioxide (SiO2) - Variety: Chalcedony

Gastropod Steinkern (Fossil Snail Internal Mold)

Class Gastropoda (Internal Mold)

Chrysocolla in Matrix

Cu2-xAlx(H2-xSi2O5)(OH)4·nH2O (Silicate/Secondary Copper Mineral)

Banded Gneiss

Gneiss (High-grade regional metamorphic rock)

Green Quartzite (with Fuchsite)

Quartzite with Muscovite variety Fuchsite (K(Al,Cr)2(AlSi3O10)(OH)2)

Amethyst (Chevron or Banded variety)

Silicon Dioxide with Iron impurities (SiO2)

Porphyritic Basalt (Chinese Writing Stone)

Porphyritic Basalt or Porphyritic Andesite

Quartz (Milky Quartz)

Silicon Dioxide (SiO2)

Petrified Wood

Silicified Wood (primarily Quartz/Chalcedony, formula SiO2)

Sandstone (with manganese staining)

Clastic sedimentary rock (primarily SiO2)

Sandstone (Banded)

Clastic Sedimentary Rock (primarily SiO2)

Basalt (Polished)

Basalt (Mafic Extrusive Igneous Rock)

Pebble (likely Quartzite or Chert)

Clastic Sediment, potentially composed of SiO₂ (Quartz)

Basalt (River Rock/Cobble)

Basalt (no specific mineral formula as it's a rock)

Quartzite

Quartzite (primarily SiO2)

Lapis Lazuli

Na8[Al6Si6O24]S2 (Lazurite component), a rock composed primarily of Lazurite, Calcite, and Pyrite

Quartzite

Quartzite (SiO2)

White Agate (Chalcedony)

Silicon Dioxide (SiO2)

Copper-bearing Quartz (with Malachite and Iron Oxides)

Quartz (SiO2) with Malachite (Cu2CO3(OH)2) and Hematite/Limonite (Fe2O3)

Yellow Quartzite

Quartzite (SiO2)

Chert (Jasper/Iron-stained Quartzite)

Silicon Dioxide (SiO2)

Sandstone

Arenite (SiO2 based)

Sandstone

Arenite (composed primarily of SiO2)