Not A Natural Rock (Man Made Composite)

Blue Dyed Agate Slice

Silicon Dioxide (SiO2) with artificial pigment

Granite

Granite (Phaneritic intrusive igneous rock) - Composition: SiO2, Al2O3, K2O, Na2O

Dyed Purple Agate Sliced

Silicon Dioxide (SiO2) with artificial pigment

Sandstone

Sandstone (Clastic Sedimentary Rock)

Amethyst (Faceted)

Amethyst (Silicon Dioxide with iron impurities, SiO2)

Clear Quartz

Silicon Dioxide (SiO2)

Turquoise

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

Tumbled gray stone, likely serpentinite or weathered basalt

Tentatively serpentinite (predominantly serpentine-group minerals); identification is uncertain from the photograph

Black Granite

Phaneritic Mafic Igneous Rock (likely Gabbronorite or Dolerite)

Eye Agate

Silicon Dioxide (SiO2) - Banded Chalcedony

Shale

Fissile Mudstone (primarily composed of clay minerals and quartz)

Tumbled tree agate (dendritic agate)

Cryptocrystalline quartz, SiO₂, with manganese/iron-oxide dendrites

Rounded quartz-rich cobble, likely granite-derived stone

Granite or granitic gneiss, composed mainly of quartz, feldspar, and minor mica

Banded Gneiss

Gneiss (pronounced 'nice')

Clear Quartz (Tumbled)

Silicon Dioxide (SiO2)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Polished pink chalcedony (likely pink agate/geode)

Microcrystalline quartz, SiO₂; chalcedony with iron-bearing inclusions and possible druzy quartz

Halite (Rock Salt)

Halite (Sodium Chloride, NaCl)

Amethyst (Tumbled)

Purple Quartz (SiO2 with iron impurities and irradiation)

Sandstone (likely Graywacke or Arkose variant)

Clastic Sedimentary Rock (SiO2 dominated)

Marble

Marble (metamorphosed limestone or dolostone), primarily composed of calcite (CaCO3) or dolomite (CaMg(CO3)2)

River Cobble (Basalt / Gabbro)

Mafic Igneous Rock (Basaltic / Gabbroic Composition)

Dyed Agate

Silicon Dioxide (SiO2) - variety Chalcedony

Gold

Aurum (Au)

Tumbled quartz-rich pebble

Microcrystalline quartz (SiO₂), possibly weathered chert or chalcedony

Shale or Argillite

Shale (fine-grained clastic sedimentary rock) or Argillite (low-grade metamorphic rock derived from shale)

Bull Quartz with Mica and Host Rock

Massive Quartz (SiO2) with Muscovite/Chlorite inclusions

Precious Red Coral

Corallium rubrum (Calcium Carbonate, CaCO3)

Pink Granite

Phaneritic intrusive felsic igneous rock

Banded Agate (specifically Eye Agate / Chalcedony)

Agate (Cryptocrystalline variety of Quartz, SiO2)

Polished ocean jasper / orbicular jasper

Microcrystalline quartz (chalcedony), SiO₂, with iron-oxide and other mineral inclusions

Quartz Druze (on Matrix)

Silicon Dioxide (SiO2)

Granite

Phaneritic Felsic Igneous Rock (primarily Quartz, Feldspar, and Mica)

Carnelian

Carnelian (Silicon Dioxide - SiO2)

Green aventurine beads

Quartz (SiO₂), typically green quartzite/aventurine with fuchsite mica inclusions

Septarian Nodule

Septarian Concretion (CaCO3, CaMg(CO3)2, SiO2)

River Quartzite or Chert Pebble

Quartzite (primarily Silicon Dioxide - SiO2)

Herkimer Diamond

Double-Terminated Quartz (SiO2)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Granite

Granite (phaneritic intrusive igneous rock consisting mainly of quartz, alkali feldspar, and plagioclase)

Unknown Organic Object (likely a berry or fruit)

Not applicable; this is not a geological specimen. If it were a cranberry, its scientific name would be Vaccinium macrocarpon; if a cherry, it would be Prunus avium or Prunus cerasus.

Rounded gray river pebble, likely basalt or andesite

Fine-grained mafic to intermediate volcanic rock; commonly basalt (plagioclase + pyroxene, sometimes olivine)