Not A Rock (Man Made Origin)

Slag (Industrial Glass/Metal)

Ferrous slag or Glassy silicate byproduct

Granite

Felsic Plutonic Rock (primarily Quartz, Potassium Feldspar, and Plagioclase)

Banded quartz-rich rock (possibly pegmatite)

Likely quartz–feldspar pegmatite; identification is tentative from the photo

River Rock (Basalt/Greywacke pebbles)

Fluvial gravel primarily composed of Mafic Volcanic Rock (Basalt) or Lithic Sandstone (Greywacke)

Rounded river pebble (likely weathered basalt or andesite)

Fine-grained mafic to intermediate volcanic rock; exact identification requires testing or a fresh surface

Porphyritic Basalt (Chinese Writing Stone/Flower Stone)

Porphyritic Basalt (primarily Plagioclase Feldspar in a Mafic groundmass)

Mica Schist

Mica Schist (principally Biotite/Muscovite, Quartz, and Feldspar)

Porphyritic volcanic rock (likely andesite porphyry)

Porphyritic andesite; composition cannot be confirmed from the photograph

Natural Pearl

Calcium carbonate (primarily Aragonite and Conchiolin), CaCO3

Brecciated Jasper or Agatized Dinosaur Bone

SiO2

Pyrite in Host Rock

Iron Disulfide (FeS2)

Pink Aragonite

CaCO3

Quartz-rich rock fragment, likely milky quartz with iron staining

Quartz (SiO₂), possibly in a quartz-rich vein rock

Amethyst (Faceted)

Amethyst (Silicon Dioxide with iron impurities, SiO2)

Turquoise

Hydrated phosphate of copper and aluminium (CuAl6(PO4)4(OH)8·4H2O)

Chalk

Carbonate rock (mainly CaCO3)

Likely iron-rich meteorite or weathered sulfide-bearing rock

Unconfirmed; possible ordinary chondrite (stony meteorite) or iron-oxide/sulfide-bearing terrestrial rock

Granite

Granite (Felsic intrusive igneous rock)

Fossil Coral

Anthozoa (Scleractinia)

Fossiliferous Limestone with Crinoid Stem

Sedimentary Rock with Crinoidea Fossil

Basalt

Basalt (Mafic volcanic rock)

Chondrite Meteorite

Stony Meteorite (Ordinary Chondrite)

Sandstone (Pebble)

Sandstone (SiO2 with matrix/cement)

Granite

Phaneritic Felsic Igneous Rock

Quartz (specifically Milky or Iron-stained Quartz)

Silicon Dioxide (SiO2)

Zircon

Zircon (Zirconium Silicate - ZrSiO4)

Anthropogenic Heat Source (Electronic/Industrial Interface)

Thermal IR emission (Electronic infrastructure)

Dark mafic rock fragments, possibly basalt

Basalt (fine-grained plagioclase–pyroxene rock), tentative

Smoky Quartz

Silicon dioxide (SiO2)

Mixed rock and mineral specimen collection

Multiple species, likely quartz (SiO₂), calcite (CaCO₃), feldspar, chert, and assorted volcanic/sedimentary rocks

Limestone

Sedimentary Rock (Primarily Calcium Carbonate, CaCO3)

Chert (and Agate/Chalcedony)

Microcrystalline Quartz (SiO2)

Fossilized ammonite

Ammonoidea (likely a small, chambered ammonite fossil)

Sandstone

Arenite (SiO2 primarily)

Weathered gray rock, possibly basalt or andesite

Indeterminate fine-grained volcanic rock; likely basaltic-andesitic composition

Asphalt Chunk (with aggregate)

Bituminous concrete / Anthropogenic conglomerate

Iron meteorite candidate

Fe–Ni metallic meteorite, possibly an ordinary octahedrite

Quartz Sandstone Pebble

Sandstone (SiO2 dominated)

Aura Quartz (Anomalously Coated Quartz)

Silicon Dioxide (SiO2) treated with vaporized metals

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

Indeterminate quartz–feldspar aggregate with iron-oxide staining; likely granitic or hydrothermal material

Weathered quartz-rich pebble

Quartzite or silicified sandstone; predominantly microcrystalline quartz (SiO₂)

Weathered iron-rich sandstone or lateritic rock

Ferruginous sandstone/laterite; chiefly quartz (SiO₂) with iron oxides such as hematite and goethite