Sedimentary Rock (Possibly Composed Of Various Minerals)

Granite

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

Tumbled Quartz

Silicon Dioxide (SiO2)

Chert

Chert (Microcrystalline Quartz, SiO2)

Granite

Granite (Phaneritic igneous rock)

Septarian Nodule

Septarian Concretion (Calcium Carbonate/Aragonite/Calcite)

Serpentinite

Serpentinite (composed primarily of Serpentine minerals: Mg3Si2O5(OH)4)

Gneiss (Granitic Gneiss)

Gneiss (composed primarily of Quartz, Feldspar, and Mica/Amphibole)

Tumbled quartz-rich rock, likely granite or granitic gneiss

Granite/granitic gneiss; chiefly quartz (SiO₂), feldspars, and minor mica/amphibole

Botryoidal chalcedony (possibly agate/geode material)

Microcrystalline quartz, SiO₂; commonly chalcedony with quartz-lined cavities and iron-oxide staining

Red Jasper (possibly with Quartz or Hematite)

Silicon Dioxide (SiO2) with iron oxide impurities

Limestone

Sedimentary rock composed primarily of Calcite (CaCO3)

Small pale mineral fragment

Unidentified; possibly quartz, calcite, or feldspar

Leopard Skin Jasper

Silicon Dioxide (SiO2) with various inclusions

Red Jasper

Silicon Dioxide (SiO2) with Hematite inclusions

Graphic Granite (Zebra Rock)

Pegmatitic Granite (composed of Quartz and K-Feldspar)

Honey-colored chalcedony (possibly yellow/orange agate or carnelian)

Chalcedony, a microcrystalline variety of quartz; SiO₂. The color may result from iron-oxide inclusions. Exact identification is uncertain from a photograph alone.

Conglomerate

Clastic sedimentary rock (composed mostly of SiO2)

Clear Quartz Crystal

Quartz (Silicon Dioxide, SiO2)

Chalk / Sedimentary Limestone

Calcium Carbonate (CaCO3) - Biogenic Sedimentary Rock

Granite (Pebble)

Granite (composed of Quartz, Feldspar, and Mica/Amphibole)

Chert (Flint)

Microcrystalline Quartz (SiO2)

Yellow Quartzite Pebble

Quartzite (SiO2)

Weathered fossiliferous limestone

Bioclastic limestone, chiefly calcite (CaCO₃)

Unopened Geode

Geode (containing various mineralization like Quartz SiO2)

Gastropod Fossil (Snail Steinkern)

Class Gastropoda fossil, composed of Calcium Carbonate (CaCO3)

Sandstone (River Cobble)

Clastic sedimentary rock (primarily SiO2 with various lithic fragments)

Diorite

Intermediate Phaneritic Igneous Rock (Diorite)

Red Sandstone

Arenite (Ferruginous Sandstone)

Granite

Intrusive Igneous Rock

Green Calcite

Calcium Carbonate (CaCO3)

Metal Alloy (Likely Pewter or Sterling Silver)

Not a natural geological specimen; composed of refined metals. If pewter, it's a tin-based alloy. If sterling silver, it's 92.5% silver and 7.5% other metals (usually copper).

Granite

Felsic intrusive igneous rock

Shale (Beach-worn)

Laminated Pelite (primarily clay minerals and quartz)

Metallic sulfide ore, likely pyrite-bearing rock

Pyrite (FeS₂), possibly with marcasite or other sulfides

Weathered granite or granitic pegmatite

Coarse-grained quartz–feldspar–mica rock; likely granite, possibly pegmatitic granite

Shale with Plant Fossils / Carbonaceous Shale

Laminated Mudrock (Siliciclastic)

Diorite

Phaneritic Intermediate Plutonic Rock (Diorite)

Banded Gneiss Pebble

Gneiss (Metamorphic Rock)

Granite with Mafic Inclusions

Granite (Phaneritic igneous rock composed of Quartz, Feldspar, and Mica)

Bituminous Coal

Coal (Organically derived sedimentary rock)

Granite

Granite (a common rock type, not a single mineral species)

Granite

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