Mineral, Possibly Rock Fragment Containing A Mineral

Quartz-rich gneiss

Foliated quartz–feldspar–mica gneiss, possibly migmatitic

Quartz-rich rock, likely milky quartz or quartz vein fragment

Quartz (silicon dioxide, SiO₂), possibly with minor feldspar or calcite

Likely pyrite-bearing rock fragment

Pyrite (FeS₂), possibly in a weathered host rock; identification is uncertain from the image

Sandstone Pebble

Arenite (SiO2 with minor mineral cements)

Honey calcite (likely rough cleavage fragment)

Calcite, calcium carbonate (CaCO₃)

Granite Pegmatite

Pegmatite (Fulgite / Felsic Intrusive Rock)

Granite

Intrusive Igneous Rock

Small brown mineral fragment

Unidentified; the image lacks enough detail for a reliable species-level identification

Mica Schist

Mica Schist (primarily Muscovite or Biotite sheet silicates)

Asphalt aggregate pavement

Bituminous asphalt concrete containing crushed stone aggregate

Yellow chalcedony or quartz fragment

Microcrystalline quartz, SiO₂ (tentative; possibly iron-stained chalcedony)

Weathered brown rock fragment

Indeterminate; possibly ferruginous sandstone or weathered volcanic rock

Granite

Granite (Felsic Plutonic Rock)

Quartz-rich rock fragment, likely milky quartz

Quartz (silicon dioxide, SiO₂), possibly an iron-stained quartz vein fragment

Small pale blue-gray rock fragment

Unidentified fine-grained silicate rock; image insufficient for a reliable species-level identification

Serpentinite (likely)

Serpentine-group minerals, chiefly antigorite/lizardite; commonly with magnetite and relic olivine/pyroxene

Mixed rock fragments, likely basalt and weathered granite

Probable mafic volcanic rock (basalt) with granitoid fragments; exact identification is uncertain from the image

Likely fluorescent mineral specimen

Uncertain; possibly willemite (Zn₂SiO₄) or fluorite (CaF₂)

Sandstone (Greywacke)

Arenite / Clastic Sedimentary Rock

Pegmatite (Quartz, Feldspar, and Tourmaline/Biotite)

Pegmatitic Igneous Rock

Likely quartz crystal

Quartz (SiO₂), possibly milky or iron-stained quartz

Conglomerate

Conglomerate (Sedimentary rock)

Weathered quartz-rich pebble, possibly metasandstone

Quartz-rich metasandstone (provisional); mainly SiO₂ with minor feldspar, mica, or iron oxides

Likely small quartz pebble

Quartz (SiO₂), possibly a weathered quartz-rich rock fragment

Sandstone (Greywacke/Lithic Sandstone)

Clastic Sedimentary Rock (Lithic Sandstone)

Blue-gray quartz-rich pebble, possibly granite or granodiorite

Quartz–feldspar–mica aggregate; likely granodiorite (exact identification requires testing)

Likely iron-rich rock or metallic mineral fragment

Uncertain; possibly limonite/goethite-rich material or weathered iron meteorite fragment

Likely polished basalt with pale mineral inclusions

Basalt; inclusions possibly calcite, quartz, or weathered feldspar

Quartz–feldspar pegmatite fragment

Granitic pegmatite; chiefly quartz (SiO₂) and feldspar, with possible mica/amphibole

Small gray stone, possibly granite or quartz-rich pebble

Indeterminate; likely a weathered quartz–feldspar rock fragment

Unidentified greenish-gray rock fragment

Tentatively altered basalt or basaltic volcanic rock; mineral identification requires testing

Polished amber

Amber (fossilized plant resin; commonly succinite, not a mineral)

Quartz-rich breccia or quartz vein fragment

Silica, primarily quartz (SiO₂), with possible chlorite, feldspar, or iron-oxide inclusions

Sandstone (Graywacke)

Arenite / Graywacke (SiO2 with lithic fragments)

Weathered quartz-bearing rock fragments

Likely quartz (SiO₂) in a weathered iron-stained host rock; exact identification is uncertain from the image

Fossiliferous limestone pebble

Calcitic limestone, primarily CaCO₃ (calcite), containing a possible trace-fossil or shell fragment

Likely weathered quartz-bearing rock fragment

Indeterminate granitic or quartz-rich silicate rock; chiefly quartz (SiO₂), possibly feldspar

Sandstone (likely Calcareous or Micaceous)

Clastic sedimentary rock (primarily Quartz with Cementing Agents)

Green quartz pebble, possibly aventurine

Quartz (SiO₂), likely fuchsite-bearing aventurine quartz

Fossilized tooth or bone fragment

Indeterminate fossil; possibly a small fossil tooth or mineralized bone, exact identification requires microscopy

Conglomerate

Conglomerate (Clastic Sedimentary Rock)

Likely weathered quartz-rich rock or mineral fragment

Indeterminate from image; possibly quartz-bearing pegmatite or iron-stained quartz