Metamorphic Or Igneous Alteration

Weathered mafic rock, likely basalt or greenstone

Fine-grained basaltic rock; possibly altered basalt (metabasalt/greenstone)

Tumbled orbicular jasper

Orbicular jasper (microcrystalline quartz/chalcedony with iron-bearing minerals)

Serpentinite

Serpentinite; chiefly serpentine-group minerals (antigorite, lizardite, chrysotile), commonly with magnetite and talc

Polished green serpentine (likely bowenite)

Serpentine-group minerals, chiefly antigorite and/or lizardite; bowenite is a compact, nickel-bearing serpentine variety

Polished serpentine pebble

Serpentinite, chiefly serpentine-group minerals (antigorite/lizardite; approximate formula Mg3Si2O5(OH)4)

Tumbled green-brown stone, likely serpentine

Serpentinite; chiefly serpentine-group minerals (antigorite, lizardite, chrysotile), commonly with magnetite

Serpentine

Serpentine group (e.g., Antigorite, Chrysotile, Lizardite) - (Mg,Fe)3Si2O5(OH)4

Weathered basalt or volcanic scoria fragment

Basaltic volcanic rock; chiefly plagioclase, pyroxene, and iron-rich oxides

Peridotite / Olivine-rich Xenolith

Ultramafic igneous rock (predominantly olivine and pyroxene)

Unakite

Epidote–pink feldspar–quartz rock

Polished orbicular/porphyritic granite or breccia

Likely potassium-feldspar–quartz granite with amphibole/biotite and epidote; exact variety uncertain from the image

Unakite Mushroom Carving

Altered Granite (Epidote, Pink Orthoclase Feldspar, and Quartz)

Tumbled green jasper (probable serpentine-rich stone)

Jasper, microcrystalline quartz (SiO₂), possibly mixed with serpentine or chlorite

Weathered granitic rock fragments

Granite, likely quartz–feldspar–mica aggregate

Tumbled green stone, likely serpentine

Serpentinite; chiefly serpentine-group minerals (antigorite, lizardite, chrysotile)

Unakite cabochon

Unakite: epidote–K-feldspar–quartz aggregate

Unakite

Altered Granite (Granitic Metamorphic Rock)

Unakite

Altered Granite (Epidotized Granite)

Tiger's Eye (with Hematite/Magnetite matrix)

Pseudomorph of Quartz after Crocidolite (SiO2 with FeOOH/Fe2O3)

Serpentinite

Serpentinite (Mg, Fe, Ni, Al, Zn, Mn)3Si2O5(OH)4

Tiffany Stone

Fluoritized Opal Beryllium Tuff (composed of Fluorite; CaF2, Opalized SiO2, Bertrandite, Chalcedony, and Quartz)

Pink Calcite (Mangano Calcite)

Calcium Carbonate (CaCO3)

Serpentinite (probable)

Serpentinite; chiefly serpentine-group minerals (antigorite, lizardite, chrysotile), commonly with magnetite and relic olivine/pyroxene

Unakite (likely)

Epidote–pink feldspar–quartz rock; commonly termed unakite

Serpentine-rich altered rock (likely serpentinite)

Serpentinite; chiefly serpentine-group minerals, Mg₃Si₂O₅(OH)₄, with possible magnetite, talc, or chlorite

Weathered granite or granitic gneiss

Quartz–feldspar–mica rock; likely granitoid, possibly weakly gneissic

Magnetite

Magnetite (Fe3O4)

Brecciated jasper (likely ocean jasper or rhyolitic jasper)

Silica-rich volcanic breccia composed mainly of microcrystalline quartz/chalcedony (SiO₂), with iron-oxide staining and possible feldspar

Unakite

Altered Granite (composed of pink orthoclase feldspar, green epidote, and quartz)

Sugilite

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

Serpentinite

Serpentinite; chiefly serpentine-group minerals (lizardite, chrysotile, antigorite), commonly with magnetite and minor talc

Polished serpentine (likely green serpentinite)

Serpentinite; chiefly serpentine-group minerals, Mg₃Si₂O₅(OH)₄, with magnetite and possible chromite or carbonate inclusions

Tumbled serpentine (likely bowenite/antigorite)

Serpentine-group minerals, chiefly antigorite or lizardite; commonly Mg₃Si₂O₅(OH)₄

Polished serpentinite pebble

Serpentinite; primarily serpentine-group minerals (Mg3Si2O5(OH)4), with possible magnetite and talc

Serpentine

Antigorite/Chrysotile/Lizardite (Mg,Fe)3Si2O5(OH)4

Epidosite

Epidosite (Metasomatic rock consisting mainly of Epidote and Quartz)

Unakite

Unakite (Altered Granite consisting of Orthoclase KAlSi3O8, Epidote Ca2(Al,Fe)3(SiO4)3(OH), and Quartz SiO2)

Quartz-bearing altered rock, likely quartzite or hydrothermal quartz vein

Predominantly quartz (SiO₂), with possible chlorite/serpentine and iron-oxide alteration

Unakite

Epidotized Granite

Tumbled tiger’s eye

Quartz variety, chiefly SiO₂ with fibrous riebeckite/crocidolite pseudomorphs

Likely greenstone (serpentinized ultramafic rock)

Serpentinite, dominated by serpentine-group minerals (chrysotile/lizardite/antigorite), possibly with chlorite or epidote

Tumbled unakite

Unakite (epidote + pink K-feldspar + quartz)