Metamorphic (Altered Igneous Rock)

Orbicular basalt (amygdaloidal basalt)

Basalt, commonly with iron-oxide–stained amygdules; matrix chiefly plagioclase, pyroxene, and often olivine

Tiger’s eye

Quartz variety, primarily silicon dioxide (SiO₂); fibrous quartz pseudomorph after crocidolite asbestos

Talc (Soapstone variety)

Talc (Hydrated magnesium silicate) - Mg3Si4O10(OH)2

Quartz-rich breccia or altered granite fragment

Polymineralic quartz–feldspar rock, likely hydrothermally altered granite/pegmatite

Rounded weathered cobble, likely basaltic/volcanic rock

Fine-grained mafic volcanic rock, probably basalt (exact identification requires testing)

Epidote

Epidote (Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH))

Porphyritic basalt or andesite pebble

Porphyritic volcanic rock; commonly plagioclase phenocrysts in a fine mafic-to-intermediate matrix

Polished Unakite (likely)

Unakite: quartz + epidote + pink K-feldspar, commonly with minor chlorite

Erythrite on Matrix

Cobalt Bloom (Co3(AsO4)2·8H2O)

Reddish weathered volcanic rock, probably andesite

Andesite (fine-grained plagioclase–pyroxene volcanic rock), possibly altered basalt

Jasper

Silicon Dioxide (Microcrystalline Quartz, SiO2)

Rounded river pebble, likely weathered sandstone or volcanic rock

Indeterminate fine-grained lithic clast; possible sandstone (quartz-rich)

Unakite

Altered Granite (Epidotized Granite)

Unakite

Altered Granite (Epidotized Granite)

Unakite

Altered Granite (Epidotized Granite)

Unakite

Altered Granite (Epidotized Granite)

Unakite

Altered granite (Epidotized granite)

Unakite

Altered Granite (Epidotized Granite)

Unakite

Altered Granite (Epidotized Granite)

Dumortierite Quartz (Blue Quartz)

Al7(BO3)(SiO4)3O3 / Quarz with Dumortierite inclusions

Greenstone, possibly serpentine or altered basalt

Serpentinite (Mg₃Si₂O₅(OH)₄) or chlorite-epidote altered basalt; identification is uncertain from the image

Lapis Lazuli

Complex mixture of Lazurite ((Na,Ca)8(AlSiO4)6(S,SO4,Cl)1-2), Calcite, and Pyrite

Weathered basalt pebble

Basalt, a fine-grained mafic volcanic rock; likely olivine-bearing basalt

Amethyst

Silicon Dioxide (SiO2) with iron impurities

Unakite

Altered Granite (Epidotized Granite)

Polished pink-and-green feldspar-bearing rock, likely unakite or aventurine granite

Unakite-like epidote–feldspar–quartz aggregate; composition commonly K-feldspar + quartz + epidote

Weathered granite or granitic gneiss

Granite; mainly quartz (SiO₂), feldspar, and mica

Weathered basaltic rock

Basalt, likely amygdaloidal or altered basalt (plagioclase–pyroxene ± olivine)

Puddingstone / orbicular jasper-like rock

Likely orbicular rhyolite or altered volcanic breccia, composed mainly of quartz, feldspar, and iron-bearing alteration minerals

Rounded river cobble, likely basaltic rock

Fine-grained mafic volcanic rock, probably basalt or altered basalt

Ruby in Zoisite

Anyolite (composite of Corundum and Zoisite)

Unakite Pebble

Altered Granite (Epidotized Granite)

Unakite

Altered Granite (Epidotized Granite)

Weathered sandstone or arkose fragment

Quartz-rich clastic sedimentary rock; likely sandstone/arkose (dominantly SiO₂ quartz with feldspar and lithic grains)

Unakite

Unakite (epidote-bearing altered granite; mainly pink potassium feldspar, green epidote, and quartz)

Lapis Lazuli

Lapis Lazuli (Complex silicate mixture including Lazurite: (Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2)

Lapis Lazuli (Low-grade/Calcite-heavy)

Na8[Al6Si6O24]n(S,Cl,SO4,OH)2 (Lazurite component)

Polished dark green igneous pebble

Likely gabbro or diabase (dolerite), composed mainly of plagioclase feldspar and pyroxene

Quartz–feldspar-bearing metamorphic rock, likely gneiss or migmatite

Band­ed quartzofeldspathic gneiss; chiefly quartz (SiO₂), feldspar, mica, and dark amphibole/biotite

Tiger's Eye

Silicon Dioxide with Crocidolite inclusions (SiO2)

Fuchsite or Green Mica Schist

K(Al,Cr)2(AlSi3O10)(OH)2

Copper-bearing porphyritic rock (likely bornite/chalcopyrite ore)

Altered porphyritic volcanic rock with copper sulfides, chiefly bornite (Cu₅FeS₄) and/or chalcopyrite (CuFeS₂)