Metamorphic (Altered Igneous Rock)

Dumortierite Quartz (Blue Quartz)

Al7BO3(SiO4)3O3 with Quartz (SiO2)

Ruby in Fuchsite

Corundum var. Ruby in Chromium Muscovite rock

Serpentinized ultramafic rock (likely serpentinite)

Serpentinite; chiefly lizardite, antigorite, and/or chrysotile, commonly with magnetite, chromite, and residual olivine/pyroxene

Quartz-bearing altered rock

Likely quartz vein in weathered schist or gneiss; quartz is SiO₂

Likely weathered porphyritic igneous rock

Provisional identification: altered basaltic-andesite or rhyolite; exact mineralogy cannot be confirmed from this close, flash-lit image

Weathered brown mineralized rock

Likely iron-stained quartzite or quartz-rich metamorphic rock; exact identification requires testing

Gneiss (likely garnet-bearing or migmatitic gneiss)

Felsic banded gneiss; chiefly quartz, feldspar, mica, and possibly garnet

Sodalite

Na8(Al6Si6O24)Cl2

Weathered greenish rock fragment

Indeterminate; possibly epidote- or chlorite-bearing altered silicate rock

Weathered granite or granitic pegmatite fragment

Granitic rock, chiefly quartz, feldspar, and mica; exact identification requires testing

Polished gray-brown stone slab, possibly soapstone or schist

Indeterminate; likely talc-rich soapstone (steatite) or mica schist

Serpentine-rich metamorphic rock

Serpentinite, likely with quartz or calcite veining and minor magnetite

Possible weathered iron-rich rock or breccia

Indeterminate; likely iron-oxide-stained silicate rock, possibly basaltic breccia or limonite-bearing material

Polished banded river stone

Likely foliated gneiss or banded metamorphic rock; exact identification requires a fresh surface or testing

Epidosite (Unakite-related)

Epidosite (predominantly Epidote, Ca2(Al2,Fe3+)(SiO4)3(OH))

Weathered greenstone (likely serpentinite or altered basalt)

Serpentinite, primarily Mg-rich serpentine minerals; possibly chlorite/actinolite-bearing altered mafic rock

Iron-rich volcanic rock, possibly hematite-bearing basalt

Basalt with iron oxides; possible hematite/magnetite alteration

Weathered granite or granitic pebble

Granite; chiefly quartz, feldspar, and mica

Lapis lazuli pendant

Lapis lazuli; mainly lazurite (Na₃Ca(Si₃Al₃)O₁₂S), with calcite and pyrite

Weathered basaltic rock (likely basalt)

Basalt; fine-grained mafic volcanic rock composed mainly of plagioclase, pyroxene, and commonly olivine

Presumed K2 granite (K2 stone)

K2 granite, an altered granitic rock composed mainly of quartz, feldspar, and white mica, with blue azurite spots

Polished serpentine (likely green serpentinite)

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

Polished tiger iron

Tiger iron, a banded aggregate of tiger’s-eye (quartz), red jasper, and hematite/magnetite

Likely raw epidote or altered amphibole crystal

Epidote, Ca₂(Al,Fe³⁺)₃(SiO₄)₃(OH); identification is tentative from the image

Serpentinite

Serpentinite (composed primarily of Antigorite, Lizardite, or Chrysotile)

Quartz-bearing metamorphic rock, possibly epidote/quartzite

Quartz-rich rock with possible epidote and feldspar; exact identification requires testing

Rounded greenstone river cobble

Likely serpentinite or chlorite-rich metamorphic rock; exact identification requires testing

Unidentified weathered rock fragments

Likely mixed quartz- and feldspar-bearing silicate material; exact identification requires testing

Uncertain polymict breccia or altered volcanic rock

Likely hydrothermally altered volcanic breccia; exact mineral identification requires testing

Pebble of weathered basalt or andesite

Fine- to medium-grained mafic volcanic rock; commonly plagioclase ± pyroxene, olivine, and iron oxides

Weathered iron-rich rock, likely hematite–goethite-bearing basalt or ironstone

Basalt/ironstone matrix with hematite (Fe₂O₃), goethite [FeO(OH)], and possibly limonite

Tumbled iron-rich stone, possibly jasper or weathered basalt

Indeterminate; likely iron-stained microcrystalline quartz (jasper) or altered basalt

Jasper and Epidote in Quartzite

Metamorphic rock containing microcrystalline quartz, epidote, and jasper

Iron-rich quartzite or limonite-bearing rock

Quartzite (SiO₂) with iron oxides/hydroxides, chiefly hematite and goethite

Greenstone with rusty mineral patches

Greenstone (metamorphosed mafic volcanic rock; likely chlorite–epidote–actinolite assemblage)

Greenstone with Epidote or Quartz Vein

Epidiorite or Metabasalt (composed largely of Chlorite, Epidote, and Amphibole)

Likely gray-green metamorphic rock fragment

Unidentified fine-grained metamorphic rock; exact identification is not possible from this small image

Tumbled epidote-bearing rock (likely epidote–quartz–feldspar aggregate)

Epidote-rich metamorphic rock; minerals likely epidote (Ca₂(Al,Fe)₃Si₃O₁₂(OH), quartz, feldspar, and dark amphibole/biotite)

Weathered brown rock fragment, possibly iron-rich sandstone or altered basalt

Indeterminate; likely an iron-oxide–stained silicate rock

Weathered gray-green metamorphic rock, likely serpentinite or altered basalt

Serpentinite, chiefly serpentine-group minerals (antigorite/lizardite); identification is provisional from the photograph

Rounded basalt cobble

Basalt; fine-grained mafic volcanic rock, chiefly plagioclase and pyroxene with possible olivine

Unakite-like granitic pebble

Altered granite composed mainly of quartz, feldspar, and epidote; red areas may be potassium feldspar or iron-stained feldspar