Rock (Likely Sedimentary)

Weathered iron-rich rock, possibly meteorite

Uncertain; likely goethite/hematite-rich material, with meteorite possibility

Weathered quartz-rich rock, possibly granite or granitic pegmatite

Indeterminate quartz–feldspar aggregate; likely granite/pegmatite

Colorless faceted gemstone, likely cubic zirconia

Cubic zirconia (synthetic zirconium dioxide, ZrO₂); possibly colorless quartz or laboratory diamond

Quartz-rich breccia or quartzite with iron-oxide veining

Microcrystalline to granular SiO₂ (quartz), with hematite/goethite and minor feldspar or mica

Quartzite

Quartzite (SiO2)

Quartz Crystal Cluster on Matrix

Silicon Dioxide (SiO2)

Granite

Felsic intrusive igneous rock

Fossilized bivalve shell

Bivalvia indeterminate; likely a fossil cockle or clam shell, aragonite/calcite replaced or preserved

Sandstone

Clastic Sedimentary Rock

Milky quartz (likely weathered quartzite or quartz vein fragment)

Quartz, silicon dioxide (SiO₂)

Diorite

Intermediate Phaneritic Plutonic Rock - Diorite

Andesite Porphyry

Andesite (Intermediate Volcanic Rock)

Weathered iron-rich rock, possibly limonite-bearing sandstone

Limonite/goethite mixture, approximately hydrated iron oxides (FeO(OH)·nH₂O), possibly coating sandstone or ironstone

Small rounded pebble, likely quartz-rich stone

Indeterminate from photograph; possibly microcrystalline quartz (SiO₂) or a weathered silicate pebble

Likely weathered quartz-rich stone

Indeterminate; possibly quartz-bearing granite or milky quartz

Green-and-gold apatite-bearing rock, possibly epidote skarn

Apatite-group mineral, commonly fluorapatite (Ca₅(PO₄)₃F), with probable epidote and quartz; exact identification requires testing

Quartzite

Quartzite (principally SiO2)

Quartz Pebble

Silicon Dioxide (SiO2)

Milky Quartz (with Iron staining)

Silicon Dioxide (SiO2)

Orange Quartzite / Carnelian Agate

Silicon Dioxide (SiO2)

Quartz (River Pebble)

Silicon Dioxide (SiO2)

Quartzite

Quartzite (primarily SiO2)

Massive Quartz

Silicon Dioxide (SiO2)

Rough turquoise-bearing rock (probable turquoise matrix)

Turquoise, CuAl₆(PO₄)₄(OH)₈·4H₂O, likely in a host-rock matrix

Sandstone (Quartz-rich Cobble)

Arenite

Sandstone or Limestone

Sedimentary Rock

Quartz-rich rock fragment, possibly granite or quartzite

Primarily quartz (SiO₂), with possible feldspar and iron-oxide staining

Silicon

Element Si

Sand Grain (Quartz)

Silicon Dioxide (SiO2)

Weathered quartz-rich rock, possibly quartzite or quartz vein material

Quartz (SiO₂), likely with feldspar, mica, and iron-oxide staining

Unakite (likely)

Epidote–pink feldspar–quartz rock; commonly termed unakite

Basalt with Magnetite

Crystalline Basalt (Primarily Plagioclase and Pyroxene) with Magnetite (Fe3O4)

Quartzite (Iron-stained)

Quartzite (SiO2 with Fe-oxides)

Conglomerate

Conglomerate

Generic Pebble

Lithic Fragment

Likely weathered basalt or mafic volcanic rock

Basalt; chiefly plagioclase feldspar, pyroxene, and possibly olivine

Granite

Phaneritic Igneous Rock (composed of Quartz, Feldspar, and Mica)

Shale (with Iron Staining)

Argillaceous mudstone / Shale

Argillite (with Barnacles)

Argillite (metamorphosed mudstone/shale)

Granite

Phaneritic plutonic rock (SiO2 + Al2O3)

River Rock (Basalt)

Aphanitic Basaltic Rock

Chert (River Pebble/Finger Stone)

Microcrystalline quartz (SiO2)