Sedimentary Rock (Altered)

Limestone with Weathering Rind

Calcium Carbonate (CaCO3) - Bioclastic or Micritic Limestone

Weathered greenstone

Metamorphosed mafic rock, commonly chlorite–actinolite schist or altered basalt

Rounded dark pebble, likely basaltic andesite

Fine-grained mafic volcanic rock; probable basalt or andesite, identification uncertain from image alone

Unakite

Unakite (altered granitic rock)

Turquoise

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

Ironstone / limonite-rich rock

Limonite, chiefly hydrated iron oxides (FeO(OH)·nH₂O), commonly mixed with goethite and hematite

Iron-rich brown stone, possibly weathered chert or ironstone

Undetermined; likely iron-oxide-bearing silica-rich rock (chert/ironstone)

Unakite / Feldspar Veined Metamorphic Pebble

Metamorphic Rock with K-Feldspar, Epidote, and Quartz

Conglomeratic or porphyritic basalt cobble

Likely vesicular basalt with weathered feldspar/mafic inclusions; exact identification requires testing

Turquoise

Turquoise - CuAl6(PO4)4(OH)8·4H2O

Weathered porphyritic volcanic rock (likely andesite or basalt)

Porphyritic andesite/basalt; typically plagioclase feldspar ± pyroxene, olivine, and iron oxides

Greenish rock with white veins, possibly epidote or chlorite bearing rock with quartz/calcite veins

Altered mafic rock or Epidosite

Granite or granitic rock fragment

Coarse-grained felsic intrusive rock, chiefly quartz, feldspar, and mica/amphibole

Polished striped jasper pebble

Jasper, microcrystalline quartz (SiO₂) with iron-oxide and clay inclusions

Weathered volcanic rock, likely basalt

Basalt; primarily plagioclase feldspar, pyroxene, and often olivine

Dumortierite in Quartz

Silicon Dioxide with Aluminium Borosilicate (SiO2 + (Al,Fe7+)7(BO3)(SiO4)3O3)

Likely weathered basalt or andesite fragment

Fine-grained volcanic rock, likely basaltic-andesite; exact identification requires testing

Unakite

Unakite (Altered Granite)

Banded River Cobble with Mafic Dike

Hydrothermally altered Graywacke or Sandstone with Mafic Intrusion

Weathered limestone

Calcite-rich carbonate rock (mostly CaCO₃), possibly fossiliferous limestone

Lapis Lazuli

Lapis Lazuli (Metamorphic Rock containing Lazurite, Calcite, Pyrite, and Sodalite)

Granite-like rock

Felsic intrusive igneous rock, probably granitic or granodioritic

Weathered schist or gneiss boulder

Micaceous quartz-feldspar schist/gneiss; exact identification is limited by the photograph

Greenstone pebble (likely serpentinite or altered basalt)

Serpentinite, predominantly serpentine-group minerals; exact identification requires testing

Likely serpentinite (serpentine-rich rock)

Serpentine-group minerals, chiefly antigorite/lizardite; commonly derived from ultramafic peridotite

Rounded gray-green beach pebble

Likely basalt or fine-grained volcanic rock; exact identification requires testing

Unakite

Unakite (altered granite)

Weathered limestone or calcitic cave deposit

Calcite (CaCO₃), likely porous limestone/travertine

Unakite

Altered Granite (Epidotized Granite)

Unakite (Tumbled)

Unakite (altered granite)

Tumbled greenstone-like pebble

Likely serpentine or chlorite-rich metamorphic rock; exact identification requires testing

Quartz-veined metamorphic rock, likely greenschist or altered metavolcanic

Chlorite–actinolite–epidote-bearing metavolcanic rock with quartz veins; exact identification requires testing

Quartz Vein in Greenstone

Metamorphic rock with quartz vein (SiO2 / mixed silicates)

Polished jasper pebble

Jasper, microcrystalline quartz (SiO₂) with iron-oxide and clay-mineral impurities

Unakite

Altered Granite (Epidotized Granite)

Serpentine

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

Weathered porphyritic volcanic rock

Likely altered andesite or rhyolite porphyry

Amethyst

Silicon Dioxide (SiO2) with iron impurities

Unakite

Unakite (altered granite containing Epidote, Orthoclase, and Quartz)

Serpentine

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

Greenstone / Basalt with Amygdule

Amygdaloidal Basalt (altered to Greenstone)

Weathered basalt or volcanic rock

Likely vesicular basalt; composition dominated by plagioclase and pyroxene, with possible iron-oxide alteration