Metamorphic Or Igneous Alteration

Polished orbicular granite

Granite, chiefly quartz, alkali feldspar, plagioclase, and biotite/amphibole

Rounded granitic pebble

Granite, chiefly quartz–feldspar–mica; exact variety uncertain from the image

Pink granite (weathered, rounded cobble)

Granite; predominantly quartz, potassium feldspar, plagioclase, and mica/amphibole

Nephrite Jade

Nephrite

Quartz-bearing ironstone or breccia

Silicified iron-rich breccia; mainly quartz (SiO₂), iron oxides/hydroxides, and altered host rock

Chrysocolla on Matrix

Hydrated copper silicates ((Cu,Al)2H2Si2O5(OH)4·nH2O)

Quartz-rich granitic rock, possibly pegmatite

Granite or granitic pegmatite; primarily quartz (SiO₂), feldspar, and minor mica/iron oxides

Polished ocean jasper (orbicular jasper), likely

Silica-rich microcrystalline quartz/chalcedony aggregate, commonly with feldspar, epidote, and iron oxides; composition varies

Basalt Pebble

Aphanitic Mafic Igneous Rock

Magnetite

Magnetite (Fe3O4)

Apatite

Fluorapatite / Chlorapatite (Ca5(PO4)3(F,Cl,OH))

Greenstone, likely altered basalt

Metabasalt (chlorite–actinolite–epidote assemblage), likely greenschist-facies greenstone

Rounded basalt cobble

Basalt, a fine-grained mafic volcanic rock composed mainly of plagioclase and pyroxene, commonly with minor olivine and iron oxides

Weathered granite or granitic gneiss

Granite: quartz, feldspar, and mica; possibly weakly foliated gneiss

Mixed rock and mineral specimens

Predominantly quartz-rich rocks, with a possible malachite-bearing specimen; exact identification is uncertain from the image

Weathered basaltic rock (probable basalt)

Basalt; fine-grained mafic silicate rock, commonly plagioclase + pyroxene ± olivine

Olivine Basalt (with Epidote and Serpentine)

Mafic Volcanic Rock (Basalt)

Coarse-grained Granite

Granitoid (Felsic Plutonic Rock)

Serpentinite

Serpentinite (Mg, Fe, Ni, Al, Zn, Mn)2-3(Si, Al, Fe)2O5(OH)4

Diorite with Quartz Vein

Intermediate plutonic igneous rock (Diorite / Metagabbro with SiO2 quartz alteration)

Quartz-rich conglomeratic rock (likely granitic breccia or conglomerate)

Uncertain; quartz–feldspar rock in a fine-grained matrix, possibly weathered granite or polymictic conglomerate

Weathered basaltic rock (likely basalt)

Basalt; primarily plagioclase feldspar, pyroxene, and possibly olivine, with surface alteration minerals

Zoisite with Hornblende

Zoisite (Ca2Al3(SiO4)3(OH)) with Amphibole inclusions

Tumbled sodalite

Sodalite, Na₈(Al₆Si₆O₂₄)Cl₂

Weathered vesicular volcanic rock (likely scoria or vesicular basalt)

Vesicular basalt/scoria; primarily plagioclase, pyroxene, olivine, and volcanic glass

Weathered dark igneous rock, likely basalt

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

Iron-stained quartz-rich rock, possibly weathered granite or pegmatite

Quartz (SiO₂) with probable feldspar and iron-oxide staining; exact identification is uncertain from the photograph

Granite (weathered)

Felsic Intrusive Igneous Rock (composed of Quartz, Alkali Feldspar, and Plagioclase)

Basalt (with possible alteration or lichen)

Mafic volcanic rock (primarily Plagioclase and Pyroxene)

Basalt with Epidote Veining

Basalt (Mafic Extrusive Rock) with Ca2(Al,Fe)3(SiO4)3(OH)

Unakite

Altered Granite (Epidotized Granite)

Serpentinite pebble

Serpentinite; chiefly serpentine-group minerals, Mg₃Si₂O₅(OH)₄, with magnetite and accessory chlorite/talc

Basalt (Greenstone/Trap Rock)

Basalt (dominated by plagioclase feldspar and pyroxene)

Bornite

Bornite (Cu5FeS4)

Weathered basalt (likely vesicular basalt)

Basalt; primarily plagioclase feldspar, pyroxene, and often olivine (approx. 45–52% SiO₂)

Weathered basalt (likely)

Basalt; fine-grained mafic volcanic rock, chiefly plagioclase and pyroxene with possible olivine

Likely basalt or gabbro

Mafic igneous rock, chiefly plagioclase feldspar and pyroxene; possible olivine

Vesicular basalt (scoriaceous basalt)

Basalt; chiefly plagioclase feldspar, pyroxene, and often olivine

Quartz Pebble

Silicon Dioxide (SiO2)

Apatite

Fluorapatite (Ca5(PO4)3F)

Clear Quartz

Silicon Dioxide (SiO2)

Mica

Mica group (often Muscovite or Biotite)