Sedimentary Or Igneous Fragment

Banded Gneiss

Gneiss

Quartz Druzy (on Geode Fragments)

Silicon Dioxide (SiO2)

Quartz / Common Gravel

Silicon Dioxide (SiO2)

Banded Gneiss / Metamorphic River Pebble

Gneiss (Foliated Metamorphic Rock)

Quartz Pebble

Silicon Dioxide (SiO2)

Unidentifiable Specimen

Undetermined

Massive White Quartz

Silicon Dioxide (SiO2)

Weathered quartz-rich rock fragment

Likely quartz-bearing feldspathic rock; exact identification requires testing

Banded Chert / Cryptocrystalline Quartz

Silicon Dioxide (SiO2)

Basalt Fragment

Extrusive Igneous Rock

Quartz Pebble

Silicon Dioxide (SiO2)

Small weathered stone, possibly quartz-rich granite or feldspar

Indeterminate granitoid fragment; likely quartz (SiO₂) and feldspar, with minor mica or iron oxides

Pyrite (Fool's Gold)

Iron Disulfide (FeS2)

Chalcedony (Agate/Chert variety)

Silicon Dioxide (SiO2)

Moss-covered Rock Fragment

Weathered Rock Fragment with Epilithic Growth

Chalcedony Geode Fragment

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Sandstone (Ferruginous)

Arenite with Iron Oxide cement

Chert (Jasper/Flint variety)

Microcrystalline Quartz (SiO2)

Weathered, quartz-rich metamorphic rock (likely schist or gneiss)

Quartz–feldspar–mica schist/gneiss, with surface lichens and iron-oxide staining

Gravel / Crushed Stone

Aggregate (mixed mineral rock fragments)

Gneiss (Gneissic Granite Pebble)

Metamorphic rock rich in Quartz, Feldspar, and Mica

River Pebble

Polished Rock Fragment

Fossilized Bone Chunk (likely Dinosaur or Large Mammal)

Permineralized Fossil Bone

Probable amber fragment

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

Raw Sunstone

Sunstone (Feldspar variety, (Ca,Na)((Al,Si)2Si2O8))

Likely hematite-rich ironstone or metallic mineral fragment

Hematite (Fe₂O₃), possibly with magnetite (Fe₃O₄) or metallic iron

Granite Pebble

Granite (composed primarily of Quartz, Feldspar, and Mica)

Milky Quartz

Silicon Dioxide (SiO2)

Orthoclase Feldspar

Orthoclase (KAlSi3O8)

Basalt Fragment

Extrusive Igneous Rock

Banded Agate / Shell Fossil Fragment

Silicon Dioxide (SiO2) / Calcium Carbonate (CaCO3)

Quartz (or Chalcedony) Specimen

Silicon Dioxide (SiO2)

Quartz (Iron-stained)

Silicon Dioxide (SiO2)

Clear Quartz

Silicon Dioxide (SiO2)

Likely weathered sandstone fragment

Sandstone, chiefly quartz (SiO₂) with feldspar and iron-oxide cement

Granite

Granite (Felsic Plutonic Rock)

Pebble

Lithified rock fragment / Sedimentary clast

Oyster Shell Fragment

Crassostrea virginica (or related Bivalvia)

Granite fragment

Granite (Felsic Plutonic Rock)

Sandstone-based Concrete Fragment

Cementitious Composite with Sedimentary Aggregate

Quartz (Milky/Snow)

Silicon Dioxide (SiO2)

River Pebble (Gneiss / Granitic Schist)

Metamorphic Rock (Quartz-Feldspar-Mica assembly)