Metamorphic (Altered Igneous Rock)

Weathered iron-rich rock, possibly laterite or altered basalt

Probable ferruginous basalt/lat eritic material; exact identification requires testing

Tumbled blue-gray stone, likely basalt

Basalt (fine-grained mafic volcanic rock; chiefly plagioclase and pyroxene, commonly with magnetite)

Weathered quartz-rich rock, likely silicified limestone or quartzite

Microcrystalline quartz (SiO₂), possibly with calcite (CaCO₃) and iron-oxide staining

Nephrite Jade

Nephrite

Lapis Lazuli

Lapis lazuli (Complex silicate mixture including Lazurite, Calcite, and Pyrite)

Weathered porphyritic volcanic rock

Likely altered andesite or rhyolite porphyry

Blue quartz-bearing rock, possibly chrysocolla-bearing quartzite

Quartz (SiO₂), with probable blue chrysocolla or copper-bearing clay minerals; exact identification requires testing

Polished quartz-rich breccia

Quartz–feldspar breccia; predominantly SiO₂ with feldspar and iron-oxide minerals

Tumbled yellow jasper or iron-stained quartzite

Microcrystalline quartz (SiO₂), likely jasper/quartzite with iron-oxide staining

Orbicular jasper / brecciated jasper slab

Silicified volcanic rock composed mainly of microcrystalline quartz (SiO₂), with iron-oxide and possible chalcedony/agate bands

Likely tumbled dark volcanic rock

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

Rhyolite or jasper-bearing volcanic rock

Rhyolite, likely altered and silicified; red coloration may come from hematite

Weathered granite or granitic gneiss

Granite; predominantly quartz, feldspar, and mica, possibly altered to gneiss

Quartz Vein in Host Rock

Silicon Dioxide (SiO2) in Altered Host Rock

Dark vesicular volcanic rock, likely basalt

Basalt (predominantly plagioclase and pyroxene, with possible olivine and iron oxides)

Tiger's Eye

Pseudomorph of Quartz after Crocidolite (SiO2)

Serpentinite (probable)

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

Citrine Quartz (Yellow Quartz)

Silicon Dioxide (SiO2) with iron impurities

Lapis Lazuli

Lapis Lazuli (Complex rock containing Sodalite, Lazurite, Calcite, and Pyrite)

Banded calcite (likely marble or calcite-rich limestone)

Calcite, CaCO₃; possibly calcitic marble

Weathered reddish-brown rock fragment

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

Orbicular jasper (likely brecciated jasper)

Microcrystalline quartz/chalcedony (SiO₂) with iron-oxide and silica-rich clasts

Weathered iron-rich rock (likely basalt or ironstone)

Probable altered basalt; exact identification requires testing

Weathered iron-rich basalt or laterite

Basalt, likely limonitized/goethite-stained; exact identification requires testing

Weathered granitic rock (likely granite or granodiorite)

Granite–granodiorite; quartz + feldspar + dark mica/amphibole

Unakite (Epidote-Rich Granite)

Unakite (Granite consisting of Orthoclase, Quartz, and Epidote)

Serpentinite (serpentine-rich metamorphic rock)

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

Porphyritic Basalt

Porphyritic Mafic Volcanic Rock

Weathered quartz-rich rock fragments

Probable granite or granitic gneiss; quartz (SiO₂), feldspar, and mica

Weathered limestone or calcitic cave deposit

Calcite (CaCO₃), likely porous limestone/travertine

Weathered basaltic volcanic rock

Basalt, likely vesicular/amygdaloidal basalt

Serpentine-rich metamorphic rock (possibly serpentinite)

Serpentinite; chiefly antigorite, lizardite, or chrysotile with possible magnetite and carbonate minerals

Greenstone pebble

Likely chlorite- or epidote-bearing metamafic rock (metabasalt/greenschist)

Vesicular volcanic rock, likely pumice or weathered scoria

Pumice/scoria; predominantly volcanic glass and plagioclase, with possible pyroxene or iron oxides

Serpentine-rich altered rock (likely serpentinite)

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

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

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

Likely weathered quartz-bearing rock fragment

Indeterminate granitic or quartz-rich silicate rock; chiefly quartz (SiO₂), possibly feldspar

Unakite

Epidotized Granite

Weathered porphyritic volcanic rock, likely andesite

Porphyritic andesite; primarily plagioclase feldspar, pyroxene, and possibly amphibole in a fine-grained groundmass

Tiger's Eye

Pseudomorph of Quartz after Crocidolite (SiO2)

Weathered quartz-rich metamorphic rock (probable quartzite)

Quartzite; predominantly microcrystalline quartz (SiO₂), with possible mica, feldspar, and iron-oxide impurities

Unakite (likely)

Epidote–K-feldspar–quartz aggregate; epidote: Ca₂(Al,Fe³⁺)₃Si₃O₁₂(OH)