Metamorphic Or Igneous Alteration

Tiger’s eye

Quartz (SiO₂) with fibrous crocidolite pseudomorphs and iron oxides

Tumbled tiger’s-eye

Quartz variety, SiO₂, with crocidolite-derived fibrous inclusions

Tumbled river pebble, likely basaltic andesite

Fine-grained mafic volcanic rock; composition likely plagioclase, pyroxene, and minor iron oxides

Greenstone / Basalt

Aphanitic Mafic Igneous Rock (likely altered Basalt)

Serpentine-rich rock

Serpentinite; chiefly serpentine-group minerals, Mg₃Si₂O₅(OH)₄

Polished serpentine-rich rock (likely serpentinite)

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

Serpentinite

Serpentinite (composed primarily of Serpentine group minerals such as Antigorite, Lizardite, and Chrysotile)

Charoite

Charoite (Hydrated potassium sodium calcium barium strontium silicate hydroxyfluoride)

Stichtite in Serpentine (Atlantisite)

Mg6Cr2CO3(OH)16·4H2O (Stichtite) within Mg3Si2O5(OH)4 (Serpentine)

Unakite or Red Jasper in Epidote

Unakite (Metasomatized Granite)

Unakite (weathered pebble)

Unakite: epidote-bearing granitoid, typically quartz + pink potassium feldspar + green epidote

Granite (likely weathered granitic rock)

Granite; primarily quartz (SiO₂), feldspar, and mica/amphibole

Weathered basaltic rock

Basalt, likely altered basalt (plagioclase–pyroxene ± olivine; possible iron-oxide staining)

Dark green-gray basalt (possibly metabasalt/greenstone)

Basalt; chiefly plagioclase feldspar and pyroxene, with possible chlorite/actinolite alteration

Basalt (with possible Serpentinization)

Mafic Igneous Rock (primarily Plagioclase and Pyroxene)

Weathered quartz-rich pebble

Likely quartzite or quartz-bearing granitoid; exact identification requires testing

Greenstone pebble (likely altered basalt or serpentine)

Greenschist-facies mafic rock; commonly chlorite–actinolite–epidote ± serpentine

Green aventurine / epidote-bearing metamorphic rock

Likely chlorite- and epidote-rich schist or altered amphibolite; exact identification requires testing

Polished serpentine (likely bowenite)

Serpentine-group minerals, chiefly antigorite; bowenite is a nickel-rich translucent variety

Weathered serpentinite (likely serpentine-rich rock)

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

Tumbled nephrite jade (likely)

Nephrite jade; fibrous amphibole aggregate, chiefly actinolite–tremolite, Ca₂(Mg,Fe)₅Si₈O₂₂(OH)₂

Serpentine (likely serpentinized ultramafic rock)

Serpentine-group minerals, chiefly antigorite, lizardite, or chrysotile; commonly derived from peridotite

Carved nephrite jade pendant

Nephrite jade; interlocking tremolite–actinolite amphibole, Ca₂(Mg,Fe)₅Si₈O₂₂(OH)₂

Weathered mafic rock fragment

Likely basalt or volcanic breccia; identification is uncertain from the photograph

Weathered volcanic rock fragment

Likely andesite or basalt; exact identification requires fresh surface and testing

Serpentinite (likely serpentinized ultramafic rock)

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

Likely dark green jasper or serpentinite pebble

Undetermined fine-grained rock; possible serpentine-group mineral (approx. Mg₃Si₂O₅(OH)₄) or jasper (microcrystalline SiO₂)

Polished serpentine (likely)

Serpentine-group minerals, chiefly antigorite/lizardite; commonly associated with magnetite and chromite

Unakite

Unakite (Epidotized Granite)

Unakite

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

Greenstone / Serpentinite

Serpentinite (composed primarily of minerals from the serpentine group Mg3Si2O5(OH)4)

Red Tiger's Eye

Pseudomorph of Quartz after Crocidolite (SiO2 with Fe2O3 inclusions)

Stichtite in Serpentine (Atlantisite)

Mg6Cr2CO3(OH)16·4H2O (Stichtite) within Mg3Si2O5(OH)4 (Serpentine)

Tumbled serpentine

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

Serpentinite (probable)

Serpentinite, dominated by serpentine-group minerals (chrysotile, lizardite, or antigorite), commonly with magnetite

Dark green mineral specimen, possibly serpentine or epidote

Tentatively serpentine-group mineral, Mg₃Si₂O₅(OH)₄, or epidote, Ca₂(Al,Fe)₃Si₃O₁₂(OH)

Greenstone / altered basalt fragment

Likely chlorite–epidote–actinolite altered basalt; exact identification requires testing

Tumbled kiwi jasper (often sold as sesame jasper)

Trade name for a green, quartz-rich rock, commonly a mixture of quartz/chalcedony and dark mineral inclusions; not a single defined mineral species

Dark green-black stone, possibly serpentinite

Serpentinite (predominantly serpentine-group minerals; identification from photo is uncertain)

Tumbled green stone, likely serpentine

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

Unakite

Altered Granite (Orthoclase Feldspar, Epidote, and Quartz)

Serpentine (Serpentinite)

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