Sedimentary Or Igneous Fragment

Clear calcite cleavage fragment

Calcite (calcium carbonate, CaCO₃)

Gneiss

Gneiss

Quartzite with Mica / Gneiss Pebble

Metamorphic Rock (Quartz-Feldspar-Mica aggregate)

Banded calcite (likely cave deposit or vein fragment)

Calcite, CaCO₃

Coquina / Fossiliferous Limestone

Fossiliferous Limestone / CaCO3

Druzy Quartz (on Geode Fragment)

Silicon Dioxide (SiO2)

Granite fragment

Granite

Polished fossiliferous limestone

Bioclastic limestone, chiefly calcite (CaCO₃)

Quartz-rich vein rock, likely milky quartz in weathered host rock

Milky quartz (SiO₂), probably with weathered feldspar and iron-oxide staining

Likely weathered granite or granitic gneiss

Granite: quartz + feldspar + mica; possibly gneiss if foliation is present

Small quartz crystal fragment (probable)

Quartz, silicon dioxide (SiO₂)

Milky quartz

Quartz (silicon dioxide, SiO₂)

Conglomeratic concrete or asphalt aggregate surface with dark bituminous chunks

Polymictic gravel aggregate; dark pieces likely bitumen/asphalt, not a natural rock

River Stone (Chalcedony/Jasper variety)

Microcrystalline Quartz (SiO2)

Clear Quartz

SiO2 (Silicon Dioxide)

Quartz

Silicon Dioxide (SiO2)

Decorative mosaic cross containing mixed rock and glass fragments

Polychrome aggregate; likely quartz, feldspar, marble, granite, and assorted colored glass

Iron-stained quartz-rich rock, possibly weathered granite or pegmatite

Quartz (SiO₂) with probable feldspar and iron-oxide staining; exact identification is uncertain from the photograph

Weathered quartz-rich rock, likely granite or quartzite

Indeterminate; probable quartz–feldspar aggregate, possibly granitic gneiss

Rounded quartz-rich river pebbles

Alluvial gravel; commonly quartzite, chert, and quartz-bearing sandstone fragments

Banded Agate (with small Geode cavity)

Silicon Dioxide (SiO2) - Chalcedony variety

Milky quartz (quartz-rich fragment)

Quartz, silicon dioxide (SiO₂)

Probable amber fragment

Amber (fossilized plant resin; chiefly amorphous organic resin, commonly dominated by succinite)

Quartz (Common Quartz/Citrine-toned)

Silicon Dioxide (SiO2)

Unidentifiable Specimen

Undetermined

Pebble

Clast (specifically a granule or small pebble)

Pebble

Lithic fragment / Weathered rock fragment

Weathered sandstone fragment

Quartz-rich sandstone (compositionally uncertain)

Quartz Vein / Milky Quartz

Silicon Dioxide (SiO2)

Porphyritic volcanic rock, likely andesite or rhyolite

Porphyritic andesite–rhyolite; chiefly plagioclase, quartz, and altered ferromagnesian minerals in a fine groundmass

Gneiss (Green Gneiss)

Gneiss (High-grade Regional Metamorphic Rock)

Clear Quartz

Silicon Dioxide (SiO2)

Weathered sandstone or iron-stained sedimentary rock

Quartz-rich sandstone, likely ferruginous sandstone (SiO₂-dominated)

Specular Hematite

Hematite (Fe2O3)

Unknown Rock Fragment

Undetermined

Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Fossil shell fragment, likely bivalve or brachiopod

Indeterminate fossilized mollusk/brachiopod; commonly calcite (CaCO₃)

Quartz (Small Fragment)

Silicon Dioxide (SiO2)

Sedimentary Rock Fragments

Clastic Sedimentary Rock

Green Fluorite

Calcium Fluoride (CaF2)

Reddish-brown, iron-stained rock fragment

Indeterminate; possibly weathered porphyritic volcanic rock

Likely quartz-rich rock fragment

Indeterminate; possibly quartz-bearing granite or quartzite