Metamorphic Or Igneous Alteration

Polished serpentine

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

Unakite

Altered Granite (Epidotized Granite)

Unakite

Altered granite (Epidote, Orthoclase Feldspar, and Quartz)

Tiffany Stone

Bertrandite Fluorite (CaF2 + Be4Si2O7(OH)2)

Unakitized Granite

Granitic rock with epidotization

Granite with Epidote

Phaneritic intrusive igneous rock with Epidote (Ca2(Al2,Fe)(SiO4)(Si2O7)O(OH))

Basalt (with possible epidote or olivine)

Mafic Igneous Rock (primarily Plagioclase and Pyroxene)

Rounded dark river pebble

Likely basalt or fine-grained andesite; exact identification requires testing

Serpentinite with carbonate and iron-oxide alteration

Serpentinite; chiefly antigorite/lizardite Mg₃Si₂O₅(OH)₄, with magnetite, calcite, and chromian minerals

Serpentinite

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

Pyrite (likely)

Iron disulfide, FeS₂; commonly called fool’s gold

Weathered greenish-gray stone, likely serpentinite

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

Tumbled dark green stone, likely serpentine or greenstone

Serpentine-group minerals, chiefly antigorite/lizardite; possibly chlorite-rich greenstone

Dark green metamorphic rock, likely serpentinite

Serpentinite, composed mainly of serpentine-group minerals (antigorite, lizardite, or chrysotile), commonly with magnetite and minor chlorite/talc

Unakite

Altered Granite (Epidotized Granite)

Epidosite (Epidote-Quartz rock)

Epidote-rich hydrothermal rock

Unakite

Epidotized Granite

Quartz pebble

Silicon dioxide (SiO2)

Tumbled serpentinite

Serpentinite, composed chiefly of serpentine-group minerals (lizardite, antigorite, chrysotile), commonly with magnetite and chlorite

Basalt with Epidote (Flowerstone-like texture)

Amygdaloidal Basalt (silicate mineral inclusions)

Weathered quartz-rich metamorphic rock (probable quartzite)

Quartzite, primarily microcrystalline quartz (SiO₂), with possible iron-oxide staining and minor mica/feldspar

Unakite (often traded as Dragon Blood Jasper)

Epidotized Granite

Serpentinite

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

Tumbled orbicular jasper (likely kambaba jasper)

Orbicular microcrystalline quartz–chalcedony aggregate; commonly sold as kambaba jasper

Tumbled dark green stone, likely serpentine

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

Serpentinite (probable)

Serpentinite; chiefly serpentine-group minerals, commonly lizardite, chrysotile, or antigorite, with possible magnetite and relict olivine/pyroxene

Tumbled green-and-white stone, likely serpentine

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

Greenstone / serpentinized ultramafic rock (probable)

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

Dalmatian jasper

Quartz-bearing, orbicular microcrystalline silica (commonly sold as “Dalmatian jasper”; often an altered porphyritic igneous rock)

Dark fine-grained river pebble, likely basalt or diabase

Basaltic rock; chiefly plagioclase feldspar and pyroxene, with possible magnetite

Basalt with Epidote

Mafic volcanic rock with Epidote (Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH))

Smooth dark river pebble

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

Dark mafic igneous rock, likely basalt or gabbro

Basaltic rock composed chiefly of plagioclase feldspar and pyroxene, with possible olivine and iron-oxide minerals

Rounded basalt pebble

Basalt, a fine-grained mafic volcanic rock (mainly plagioclase and pyroxene)

Jade (likely Nephrite or Jadeite)

Nephrite (a variety of actinolite, Ca2(Mg,Fe)5Si8O22(OH)2) or Jadeite (NaAlSi2O6)

Polished serpentine or green jasper pebble

Likely serpentine-group silicate, chiefly antigorite/lizardite; possibly iron-rich jasper

Unakite

Unakite (Epidote-Feldspar rock)

Vesicular quartz-rich rock, possibly weathered rhyolite or hydrothermal quartz

Likely quartz (SiO₂) with altered feldspar, iron oxides, and cavities; exact identification requires testing

Garnet

Garnet Group (complex nesosilicates with general formula X3Y2(SiO4)3, where X can be Ca, Mg, Fe2+, Mn2+ and Y can be Al, Fe3+, Cr3+, V3+)

Jade (likely Nephrite Jade based on appearance)

Nephrite (a variety of actinolite, Ca2(Mg,Fe)5Si8O22(OH)2)

Green Aventurine

Quartz (Aventurine variety) - SiO₂ with Fuchsite inclusions

Quartz vein in weathered host rock

Quartz (SiO₂), likely in a weathered metamorphic or igneous matrix