Igneous, Metamorphic, And Sedimentary (Mixed Assemblage)

Diorite

Intermediate Phaneritic Igneous Rock

Likely quartz-rich stone (possibly milky quartz or quartzite)

Quartz, silicon dioxide (SiO₂), or quartzite if interlocking grains are present

Polished quartz-rich feldspar rock, possibly orbicular granite

Granite or granitic pegmatite; chiefly quartz (SiO₂), feldspar, and dark biotite/amphibole

Gray granite or granitic gneiss gravel

Granite; primarily quartz, feldspar, and mica (exact identification is uncertain from the photograph)

Granodiorite

Granodiorite (intermediate intrusive igneous rock containing plagioclase, quartz, and K-feldspar)

Pink Granite

Phaneritic Felsic Intrusive Igneous Rock

Quartz

Silicon Dioxide (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Likely quartz-bearing mineral aggregate

Quartz (SiO₂), possibly mixed with mica or feldspar

Barite

Barium Sulfate (BaSO4)

Granite Pegmatite

Pegmatite (Quartz, Feldspar, Mica)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Quartz (Rose Quartz or Jasper variety)

Silicon Dioxide (SiO2)

Quartz

Silicon Dioxide (SiO2)

Magnetite

Iron(II,III) oxide (Fe3O4)

Red Agate Sphere (or Banded Jasper/Agate)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Clear Quartz Crystal

Silicon Dioxide (SiO2)

Conglomerate

Conglomerate (Sedimentary rock containing rounded clasts)

Copper Ore

Mixed copper sulfides/oxides in gangue matrix

Mixed rock and mineral collection

Multiple specimens; visible examples may include quartz (SiO₂), amethyst (quartz), calcite (CaCO₃), and dark mafic rocks

Pyrite

Iron Sulfide (FeS2)

Granite (Pink/Red)

Phaneritic Igneous Rock (Rich in K-Feldspar)

K2 Jasper (K2 Granite)

Azulite in Granite (Quartz + Feldspar + Biotite + Azurite)

Magnetite / Ironstone

Magnetite (Fe3O4)

Blue-gray granite or granitic gneiss pebble

Granite, chiefly quartz, feldspar, and biotite/amphibole

Tumbled granite pebble

Granite, primarily quartz–feldspar–mica aggregate

Polished granite cobble

Granite, typically quartz–feldspar–biotite granite

Tumbled granite or granitic gneiss

Granite; primarily quartz, alkali feldspar, plagioclase, and mica

Coarse-grained igneous rock, likely granitic pegmatite or weathered granite

Granite/pegmatitic granite; chiefly quartz (SiO₂), feldspar, and dark mica or amphibole

Granite

Granite (Phaneritic intrusive igneous rock)

Granodiorite

Phaneritic-textured Intrusive Granodiorite

Weathered quartz-rich river pebble

Likely altered granite or granitic gneiss, composed mainly of quartz, feldspar, and minor mica/iron oxides

Black granite (likely polished gabbro or diabase)

Granitoid rock dominated by feldspar, quartz, and dark mafic minerals; exact identification requires testing

Quartz (Milky/Snow)

Silicon Dioxide (SiO2)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Quartz

Silicon Dioxide (SiO2)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

River gravel and cobbles

Mixed alluvial clasts, likely including granite, basalt, quartzite, and sandstone

Blue Quartz

Silicon Dioxide (SiO2) with inclusions

Quartz

Silicon Dioxide (SiO2)

Blue Quartz

Silicon Dioxide (SiO2) with inclusions