Mineral, Often A Rock Given Its Aggregate Nature

Vesicular Basalt (Scoria)

Extrusive Mafic Igneous Rock (primarily Plagioclase Feldspar and Pyroxene)

Red Jasper (Skull Carving)

Jasper, a cryptocrystalline variety of Quartz (SiO2)

Fancy Jasper

Silicon Dioxide (SiO2) with mineral inclusions

Iron-stained Quartz

Silicon Dioxide with Iron Oxide (SiO2 with Limonite/Hematite impurities)

Ferruginous Quartz (Iron-stained Quartz)

Silicon Dioxide with Iron Oxide (SiO2 + Fe2O3)

Quartz Pebble

Silicon Dioxide (SiO2)

Quartz

Quartz (SiO₂)

Basalt (Crushed Roadstone)

Mafic Igneous Rock (primarily Plagioclase Feldspar and Pyroxene)

Conglomerate

Conglomerate (clastic sedimentary rock)

Sandstone (Ferruginous)

Arenite (composed primarily of SiO2 with Fe2O3 cement)

Quartz Crystal (specifically a Double-Terminated variety)

Silicon Dioxide (SiO2) - Low Quartz

Geode (Unopened)

Siliceous Geode (SiO2)

Sandstone (likely Quartzose Sandstone)

Arenite (primarily SiO2)

Sandstone (River Rock)

Arenite (composed primarily of SiO2)

Granite

Granite (a felsic intrusive igneous rock composed primarily of quartz, feldspar, and mica)

Sandstone Concretion with Quartz Center

Sedimentary Clastic Rock (SiO2 matrix with Quartz core)

Clear Quartz crystals on a Matrix base (Geode fragment)

Silicon Dioxide (SiO2)

Sodalite

Sodalite (Na8Al6Si6O24Cl2)

Dalmation Stone

Peralkaline Rock (SiO2 with Arfvedsonite)

Basalt (with possible weathering or secondary mineral crust)

Basalt (Aphanitic Mafic Igneous Rock)

Green Quartz (Prasiolite variant or Aventurine)

Silicon Dioxide (SiO2)

Granite

Granite (Felsic Intrusive Igneous Rock)

Conglomerate (Red Sandstone variety)

Clastic Sedimentary Rock (Conglomeratic Sandstone)

Milky Quartz

Silicon Dioxide (SiO2)

Quartz Geode

Silicon Dioxide (SiO2) in a Secondary Formation

Sandstone

Arenite (primarily SiO2)

Yellow Quartz (Citrine Quartz variety / Ferruginous Quartz)

Silicon Dioxide (SiO2) with iron inclusions

Chert (varieties include Flint or Jasper)

Chert (cryptocrystalline quartz; SiO₂)

Granite (Weathered)

Course-grained Intrusive Igneous Rock

Vesicular Basalt (River Rock)

Afanitic Vesicular Basalt

Opal

Hydrated Silica (SiO2·nH2O)

Biotite (Black Mica)

Biotite - K(Mg,Fe)3AlSi3O10(F,OH)2

Basalt with inclusion

Basalt (Aphanitic-Porphyritic texture)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Aquamarine and clear quartz

Aquamarine (Be3Al2Si6O18), Quartz (SiO2)

Turquoise

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

Quartz

Silicon Dioxide (SiO2)

Rose Quartz

Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Basalt

Mafic Igneous Rock (composed primarily of Pyroxene and Plagioclase Feldspar)

Sandstone (likely Arkose)

Arenite (composed mainly of SiO2 with Feldspar)

Goldstone

Avventurina (Cu + SiO2 glass)