Anthropogenic (Man Made)

Sandstone

Clastic Sedimentary Rock

Rutilated Quartz

Silicon Dioxide (SiO2) with Titanium Dioxide (TiO2) inclusions

Granite (weathered)

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

Granite

Granite (High-silica plutonic rock)

Basalt

Basalt (Mafic volcanic rock)

Limonitic Sandstone with Inclusion

Limonitic Quartz Sandstone (primarily SiO2 with FeO(OH)·nH2O)

Limestone

Calcium Carbonate (CaCO3)

Granite

Granite (Mainly Quartz SiO2, K-Feldspar KAlSi3O8, and Plagioclase)

Limestone

Calcium Carbonate (CaCO3)

Sandstone (River Cobble)

Clastic sedimentary rock (primarily SiO2 with various lithic fragments)

Quartzite (Iron-stained)

Quartzite (SiO2 with iron oxides)

Sandstone

Arenicola (comprising mostly Quartz, SiO2)

Banded Chert / Banded Jasper (likely a variety of Chert/Chalcedony)

Chert (microcrystalline quartz)

Serpentinite

Serpentinite (Mg, Fe, Ni, Al, Zn, Mn)2-3(Si, Al, Fe)2O5(OH)4

Granite

Phaneritic Felsic Igneous Rock

Weathered sandstone or granitic rock fragment

Likely quartz-rich sandstone; exact identification requires testing

Sandstone (Ferruginous)

Arenite (with Iron Oxide cement)

Limestone

Calcium Carbonate (CaCO3)

Granite

Granite (a common term for a felsic intrusive igneous rock)

Sandstone Chert/Quartzite

Silicon Dioxide (SiO2) - Sedimentary Sandstone / Orthoquartzite

Chalcedony (Common Opal/Chert variety)

Silicon Dioxide (SiO2)

Limestone

Sedimentary rock composed primarily of Calcium Carbonate (CaCO3)

Granite

Granite (Felsic intrusive igneous rock)

Quartz

Silicon Dioxide (SiO2)

Malachite

Malachite (Cu2CO3(OH)2)

Quartzite

Quartzite (primarily SiO2)

Granite

Granite (Phaneritic Quartz-Feldspar Felsic Rock)

Foliated metamorphic rock, likely biotite schist

Mica schist, chiefly quartz, feldspar, and biotite mica

Pebble (likely Quartz or Chert)

SiO₂ (Silicon Dioxide) - referring to the likely main mineral composition, Quartz. If it's chert, the scientific name remains SiO₂ with a microcrystalline structure.

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Black Onyx

Cryptocrystalline Quartz (SiO2) with carbon/iron impurities

Limestone

Sedimentary Calcium Carbonate (CaCO3)

Chrysoprase

Chrysoprase (a variety of Chalcedony, SiO₂)

Orthoclase Feldspar

KAlSi3O8 (Potassium Aluminum Silicate)

Quartz

Quartz (SiO₂ - Silicon Dioxide)

Quartz (Rock Crystal)

Quartz (SiO₂ - Silicon Dioxide)

Quartz

Silicon Dioxide (SiO₂)

Sandstone

Arenite (primarily SiO2)

Quartz (likely macrocrystalline variety)

Quartz (SiO₂)

Quartz

Quartz (SiO₂ - Silicon Dioxide)

Granite

Granite (a common rock type, not a single mineral species)

Quartz

Quartz (SiO₂)