Igneous (Anthropogenic)

Basalt

Mafic Igneous Rock

Basalt

Mafic Igneous Basalt

Porphyritic basalt or andesite cobble

Fine-grained volcanic rock, likely plagioclase–pyroxene basalt/andesite

Granite Pebble (Pink/Orthoclase Granite)

Granite (rich in Potassium Feldspar / Orthoclase)

Granite (Orthoclase rich)

Granite (composed primarily of Quartz and Potassium Feldspar KAlSi3O8)

Sodalite

Sodalite (Na8(Al6Si6O24)Cl2)

Blue Apatite

Fluorapatite / Apatite group (Ca5(PO4)3(F,Cl,OH))

Quartz pebble

Silicon dioxide (SiO2)

Blue Apatite

Apatite (Ca5(PO4)3(F,Cl,OH))

Sugilite

Sugilite (KNa2(Fe,Mn,Al)2Li3Si12O30)

Green Aventurine

SiO2

Peacock Ore

Bornite (Cu5FeS4)

Dark weathered igneous cobble, likely basalt

Basalt; fine-grained mafic rock composed chiefly of plagioclase and pyroxene, commonly with olivine

Polished dark green igneous pebble

Likely gabbro or diabase (dolerite), composed mainly of plagioclase feldspar and pyroxene

Probable rough basalt or mafic igneous fragment

Fine-grained basalt, likely plagioclase–pyroxene–olivine aggregate

Dark igneous rock, likely basalt

Basalt; fine-grained mafic volcanic rock composed mainly of plagioclase and pyroxene, commonly with olivine

Dark igneous rock, likely basalt

Basalt; chiefly plagioclase feldspar, pyroxene, and possibly olivine

Dark weathered igneous rock, likely basalt

Basalt; chiefly plagioclase feldspar, pyroxene, and commonly olivine or iron oxides

Porphyritic Igneous Rock with Iron Oxide Weathering

Weathered Porphyry (containing Quartz, Feldspar, Amphibole/Biotite, and Hematite/Limonite)

Basalt (or similar Mafic Igneous Rock)

Basalt

Tumbled dark igneous rock, possibly gabbro or basalt

Likely mafic rock composed chiefly of pyroxene and plagioclase; exact identification requires testing

Likely coarse-grained igneous rock, possibly granite or gabbro

Granite (quartz–feldspar–mica) or gabbro (plagioclase–pyroxene); exact identification requires a fresh surface and testing

Likely quartz-rich igneous pebble

Uncertain; possibly granite or quartz-bearing pegmatite

Dark igneous rock, likely basalt

Basalt; chiefly plagioclase feldspar, pyroxene, and commonly olivine or iron-titanium oxides

Light-colored igneous rock, likely pumice or vesicular rhyolite

Primarily silica-rich volcanic glass and feldspar; exact identification is uncertain from the photograph

Weathered igneous rock, likely granite or granitic gneiss

Quartz–feldspar–mica aggregate; exact identification requires a fresh surface or testing

Weathered dark igneous rock, likely basalt

Basalt, predominantly plagioclase feldspar and pyroxene, with possible olivine and iron oxides

Dark igneous rock fragment, likely basalt

Basalt; commonly composed of plagioclase, pyroxene, and minor olivine or magnetite

Dark igneous rock, likely basalt

Basalt; primarily plagioclase feldspar, pyroxene, and commonly olivine or iron-titanium oxides

Feldspar-rich igneous rock, likely granite or gneiss fragment

Granite-like quartz–feldspar rock; exact identification is uncertain from the blurred image

Rounded dark igneous pebble, likely basalt

Basalt; fine-grained mafic volcanic rock composed mainly of plagioclase and pyroxene, with possible olivine

Diorite with Quartz Veins

Diorite

Basalt with Quartz Veins

Amygdaloidal Basalt (matrix) with Crystalline SiO2 (veins)

Polished orbicular stone, likely granite or diorite

Granite–diorite, composed mainly of feldspar, quartz, and dark amphibole/biotite

Biotite Mica Schist

Metamorphic Rock containing Biotite K(Mg,Fe)3AlSi3O10(OH)2

Dalmatian Jasper

Peralkaline Rhyolite (composed of Quartz, Feldspar, and Arfvedsonite)

Granite

Granite (Phaneritic intrusive igneous rock)

Dalmatian Jasper (Dalmatian Stone)

Perthitic Feldspar with Arfvedsonite/Riebeckite

Granite

Phaneritic Igneous Rock (composed primarily of Quartz, Alkali Feldspar, and Plagioclase)

Dalmatian Jasper

Peralkaline Quartz-Feldspar Rock with Arfvedsonite

Granite

Phaneritic Plutonic Felsic Rock

Granite Cobble

Granite