Sedimentary Or Metamorphic

Gneiss

Metamorphic Gneiss (High-grade regional metamorphism)

Quartz fragment

Quartz (silicon dioxide, SiO₂), likely milky or smoky quartz

Small white mineral fragment

Indeterminate; possibly quartz, calcite, or feldspar

Quartz

Silicon Dioxide (SiO2)

Quartz

Silicon Dioxide (SiO2)

White Quartz

Silicon Dioxide (SiO2)

Quartz

Silicon Dioxide (SiO2)

Rose Quartz

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

Quartz

Silicon Dioxide (SiO2)

Quartz

Silicon Dioxide (SiO2)

Quartz

Silicon Dioxide (SiO2)

Quartz

Silicon Dioxide (SiO2)

Quartz pebble

Quartz (Silicon dioxide, SiO2)

Quartz

Silicon Dioxide (SiO2)

Quartz

Silicon Dioxide (SiO2)

Quartz

Silicon Dioxide (SiO2)

Quartz

Silicon Dioxide (SiO2)

Blue Quartz

Silicon Dioxide (SiO2) with microscopic inclusions

Quartz

Silicon Dioxide (SiO2)

Quartz

Silicon Dioxide (SiO2)

Quartz

Silicon Dioxide (SiO2)

River Gravel

Polymictic gravel and pebble aggregate

Quartz

Silicon Dioxide (SiO2)

Rhodochrosite

Manganese Carbonate (MnCO3)

Pyrite

Iron Sulfide (FeS2)

Quartz (Clear Quartz / Rock Crystal)

Silicon Dioxide (SiO2)

Feldspar (Potassium Feldspar / Orthoclase)

KAlSi3O8 (Potassium Aluminum Silicate)

Polished Hematite Tower

Hematite (Fe2O3)

Quartz Pebble

Silicon Dioxide (SiO2)

Pyrite (Fool's Gold)

Iron Sulfide (FeS2)

Yellow Quartz Pebble

Silicon Dioxide (SiO2)

Galena (with Matrix)

Lead Sulfide (PbS)

Quartz

Silicon Dioxide (SiO2)

Quartz

Silicon Dioxide (SiO2)

Quartz

Silicon Dioxide (SiO2)

Magnetite

Iron(II,III) oxide (Fe3O4)

Quartz

Silicon Dioxide (SiO2)

Quartz

Silicon Dioxide (SiO2)

Quartz Pebble

Silicon Dioxide (SiO2)

Quartz

Silicon Dioxide (SiO2)

Quartz

Silicon Dioxide (SiO2)

Quartz

Silicon Dioxide (SiO2)