Sedimentary Rock (Possibly Conglomerate Or Breccia With A Quartz Vein)

Stiped Slate Beach Pebble

Low-grade Metamorphic Slate with Quartz Vein (SiO2 on Phyllosilicate base)

White quartz-rich pebble

Quartz (SiO₂), possibly milky quartz or quartzite

Pink granite

Granite, chiefly quartz, potassium feldspar, plagioclase, and biotite/hornblende

Yellow quartz, possibly citrine

Quartz (SiO₂), yellow variety likely citrine; may also be iron-stained quartz

Quartz with Spessartine Garnet and Iron Staining

Silicon Dioxide (SiO2) with Almandine-Spessartine (Mn3Al2(SiO4)3)

Brecciated jasper (likely ocean jasper or red jasper)

Microcrystalline quartz, SiO₂, with iron-oxide pigments and breccia cement

Quartz-rich pebble, possibly chert or silicified limestone

Microcrystalline quartz (SiO₂), possibly chalcedony; exact identification is uncertain from the photograph

Serpentine with Quartz Vein

Serpentinite (Mg, Fe, Ni, Al, Zn, Mn)2-3(Si, Al, Fe)2O5(OH)4 with SiO2 veins

Basalt with Quartz Vein

Mafic Igneous Rock (Basalt) with SiO2 (Quartz) Vein

Quartz Veined Quartzite or Sandstone

Quartzite with Quartz Veins (SiO2)

Quartz-veined Metamorphic Rock

Quartz-veined Schist or Gneiss

Quartz Geode Fragment

Silicon Dioxide (SiO2)

Quartz Pebble

Silicon Dioxide (SiO2)

Quartz (Milky Quartz)

Silicon Dioxide (SiO2)

Weathered sandstone or iron-stained sedimentary rock

Quartz-rich sandstone, possibly ferruginous sandstone

Quartz (Gravel Pebble)

Silicon Dioxide (SiO2)

Rounded chert or chalcedony pebble

Microcrystalline quartz (SiO₂), possibly silicified limestone or agate-like chalcedony

Porphyritic Basalt (with Olivine or Quartz phenocryst)

Porphyritic Basalt (Mafic Extrusive)

Milky Quartz

Silicon Dioxide (SiO2)

Asphalt aggregate (crushed stone in bitumen)

Artificial composite; predominantly crushed granite, basalt, limestone, and/or recycled aggregate bound by bitumen

Tumbled chalcedony or quartz-rich stone

Microcrystalline quartz, SiO₂; possibly pale chert or chalcedony

Quartz (beads)

SiO2 (Silicon Dioxide)

Weathered quartz-rich rock fragment

Likely quartz-bearing feldspathic rock; exact identification requires testing

Weathered granitic rock

Granitoid, likely biotite granite or granodiorite

Coarse-grained Granite

Granitoid (Felsic Plutonic Rock)

Likely weathered river pebble

Indeterminate lithology; possibly fine-grained sandstone, siltstone, or chert

Quartz (Vein Quartz)

Silicon Dioxide (SiO2)

Quartz Vein Rock

Silicon Dioxide (SiO2)

Mixed Gravel and Pebbles

Polylithic Alluvial Aggregate

Tumbled honey calcite (likely aragonite/calcite material)

Calcite, CaCO₃; possibly aragonite, a polymorph of CaCO₃

Quartz geode / iron-stained quartz vein rock

Quartz (SiO₂), likely with iron oxides and minor feldspar or host-rock minerals

White Quartz Pebble

Silicon Dioxide (SiO2)

Quartz-rich rock with chlorite/epidote vein

Milky quartz with green chlorite or epidote; exact identification requires testing

Gabbro (likely with Pyrite/Sulfide mineralization)

Mafic Intrusive Igneous Rock

Puddingstone

Conglomerate (Silicon Dioxide - SiO2 with various inclusions)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Sandstone (likely Conglomerate or Gritstone)

Arenite (SiO2 based)

Milky Quartz

Crystalline Silicon Dioxide (SiO2)

Quartz pebble

Silicon dioxide (SiO2)

Weathered quartz-rich rock fragment

Indeterminate; possibly weathered granite, quartzite, or rhyolite

Quartz Vein in Host Rock

Silicon Dioxide (SiO2)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)