Igneous Or Sedimentary (Anthropogenic Modification)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Turquoise

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

Milky Quartz Pebble

Quartz (Silicon Dioxide, SiO2)

Quartz-veined Sedimentary Rock

Hydrothermally veined Clastic Sedimentary Rock (SiO2 veins in Matrix)

Chert (and associated Sedimentary rocks)

Microcrystalline Silica (SiO2)

Ironstone Concretion / Limonite

Goethite and Limonite (FeO(OH)·nH2O)

Sandstone (Quartzose)

Arenite (Siliciclastic sedimentary rock)

Basalt with Scoria/Vesicular Texture

Extrusive Mafic Igneous Rock (primarily Plagioclase Feldspar and Pyroxene)

Granite Cobble (River Stone)

Felsic intrusive igneous rock (composition: Quartz, Feldspar, Mica)

Basalt

Mafic Igneous Rock (composed primarily of plagioclase feldspar and pyroxene)

Pink Granite (Potassium-rich Granite)

Phaneritic Felsic Igneous Rock (primarily SiO2, Al2O3, K2O)

Basalt

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

Granite Cobble

Granite (Phaneritic igneous rock composed of Quartz, Feldspar, and Mica)

River Pebble (Gabbro or Basalt)

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

Granite

Felsic Intrusive Igneous Rock (SiO2, Al2O3, K2O, Na2O)

Red Granite

Felsic intrusive igneous rock (K-feldspar rich Granite)

Granite Cobble

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

Pink Granite

Phaneritic Felsic Igneous Rock (Granite, rich in Potassium Feldspar)

Basalt with Plagioclase Feldspar

Basalt (mafic extrusive igneous rock) with plagioclase feldspar phenocrysts

Granite

Plutonic Igneous Rock (composed primarily of Quartz, Feldspar, and Mica)

Basalt with Limonite stains

Extrusive mafic igneous rock; Limonite (FeO(OH)·nH2O)

Pink Granite

Granite (Phaneritic igneous rock rich in Alkali Feldspar and Quartz)

Basalt River Stone

Extrusive Mafic Igneous Rock (primarily Plagioclase Feldspar and Pyroxene)

Druzy Quartz on Vesicular Basalt

Silicon Dioxide (SiO2) in an extrusive Mafic igneous host rock

Granite

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

Vesicular Basalt

Extrusive mafic igneous rock (primarily Plagioclase Feldspar and Pyroxene)

Granite

Phaneritic Igneous Rock (composed mostly of Quartz, Feldspar, and Mica)

Granite

Phaneritic Igneous Rock (composed of quartz, alkali feldspar, and plagioclase)

Granite

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

Pink Granite

Phaneritic Felsic Igneous Rock (composed of orthoclase, quartz, and plagioclase)

Granite (Pink/Potassium-rich)

Phaneritic Plutonic Felsic Igneous Rock (primarily SiO2 with KAlSi3O8)

Granite

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

Granite

Granite (a felsic intrusive igneous rock)

Aquamarine

Beryl (Be3Al2Si6O18)

Topaz

Topaz (Al2SiO4(F,OH)2)

Peridot (likely, based on color and appearance)

Olivine group mineral, specifically (Mg,Fe)2SiO4 (Forsterite-Fayalite solid solution series)

Milky Quartz

Quartz / Silicon Dioxide (SiO2)

Amethyst

Silicon Dioxide (SiO2) with iron impurities

Porphyritic Basalt or Diabase with Plagioclase Phenocrysts

Porphyritic Basalt or Diabase; Mineral: Plagioclase Feldspar

Obsidian

Amorphous volcanic glass (primarily SiO2)

Granite

Granite (composed mainly of Quartz, Feldspar, and Mica)

Amethyst

Silicon Dioxide (SiO2) with iron impurities