Antropogenic Rock (Man Made)

Basalt

Basalt (Extrusive Mafic Igneous Rock)

Pink Feldspar

Orthoclase Feldspar (KAlSi3O8)

Orthoclase Feldspar

Orthoclase (KAlSi3O8)

Red Sandstone (Iron-rich)

Ferruginous Sandstone (variable formula, primarily SiO2 + Fe2O3)

Chert (concretionary/nodular variant)

Microcrystalline Quartz (SiO2) with possible fossil or mineral inclusions

Boulder Opal

Precious Opal in Ironstone (Amorphous Hydrated Silica, SiO2·nH2O)

Basalt

Mafic volcanic rock (primarily plagioclase feldspar and pyroxene)

Granite

Granite (a felsic intrusive igneous rock)

Granite

Phaneritic Felsic Igneous Rock (Granite)

Gneiss

Gneiss (High-grade regional metamorphic rock)

Sandstone (Ferruginous)

Arenite (primarily SiO2 with Fe2O3 cement)

Rose Quartz

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

Quartzite (Milky Quartz pebble)

Silicon Dioxide (SiO2)

Red Quartzite / Metasandstone River Pebble

Quartzite (primarily SiO2 with hematite inclusions)

Iron-stained Quartzite / Chert

Silicon Dioxide (SiO2) with Hematite/Limonite impurities

Schist

Schist (primarily mica-schist)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Banded Chert (River Cobble)

Microcrystalline Quartz (SiO2)

Red Jasper

Silicon dioxide (SiO2) with iron oxide inclusions

Hypersthene

Hypersthene (formula: (Mg,Fe)SiO3)

Ferruginous Siltstone or Mudstone

Ferruginous Siltstone / Goethitic Sandstone

Quartz (Milky and Smoky variety)

Silicon Dioxide (SiO2)

Scoria

Extrusive Igneous Rock (Basaltic/Andesitic Composition)

Quartz Pebble

Silicon Dioxide (SiO2)

Quartz Pebble (Iron-stained)

Silicon Dioxide (SiO2)

Red Jasper (Heliotrope family variant)

Silicon Dioxide with Hematite inclusions (SiO2 + Fe2O3)

Quartz Pebble (Geode-like)

Silicon Dioxide (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Pink Granite

Granite (composed primarily of Quartz, K-Feldspar, and Plagioclase)

Limonite-stained Quartz / Quartzite

Silicon Dioxide (SiO2) with iron hydroxides (FeO(OH)·nH2O)

Quartz (Vein Quartz)

Silicon Dioxide (SiO2)

Travertine (Tufa)

Chemical Sedimentary Limestone (CaCO3)

River Cobble (Quartzite with Iron Staining)

Metamorphic Quartzite (SiO2 with Fe2O3 inclusions)

Tufa

Calcareous Tufa (CaCO3)

Porphyritic Basalt

Porphyritic Basalt (Mafic extrusive rock)

Basalt River Pebble

Basalt (Aphanitic Mafic Volcanic Rock)

Basalt

Basalt (Aphanitic Mafic Igneous Rock)

Granite (Pink/Red Orthoclase variety)

Phaneritic Plutonic Felsic Rock (SiO2, KAlSi3O8, NaAlSi3O8, CaAl2Si2O8)

Sandstone

Clastic Sedimentary Rock (composed mostly of quartz and/or feldspar)

Granite

Granite (a felsic intrusive igneous rock)

Granite

Granite (Felsic intrusive igneous rock)

Porphyritic Basalt (Chinese Writing Stone or Flower Stone)

Porphyritic Basalt / Porphyry