Sedimentary Rock (Metamorphosed)

Anthracite Coal

Anthracite (Highly Metamorphosed Coal)

Anthracite Coal

Anthracite (Metamorphosed Bituminous Coal)

Anthracite Coal

Anthracite (Highly Metamorphosed Coal)

Weathered quartz-rich rock, likely milky quartz/quartzite

Quartz (SiO₂), possibly quartzite with minor iron-oxide staining

Likely purple quartzite or purple chert

Quartzite/chert, predominantly microcrystalline SiO₂; exact identification requires testing

Greenstone / altered mafic rock

Likely chlorite–actinolite schist or metabasalt; exact identification requires testing

Quartzite with Quartz Veining

Metamorphosed Quartz-rich Sandstone (SiO2)

Quartz-rich granite or granitic gneiss

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

Quartzite with Hematite staining

Metamorphosed Quartz-rich sandstone (SiO2)

Quartzite

Quartzite (primarily SiO2)

Tumbled speckled pebble, likely marble or limestone

Calcite-rich carbonate rock; possibly impure marble (CaCO₃)

Zebra Marble

Metamorphosed Alabaster/Limestone (CaCO3)

Quartzite with Epidote

Meta-quartzite containing Epidote (Ca2(Al2,Fe)(SiO4)(Si2O7)O(OH))

Quartzite (River Pebble)

Metamorphosed Quartz-rich Sandstone (SiO2)

Serpentinized ultramafic rock (likely serpentinite)

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

Quartzite with Schist Inclusions

Metamorphosed Quartzite (SiO2) with minor mica/chlorite schist

Graphite-rich schist (probable graphite ore)

Graphite schist; chiefly graphitic carbon (C) with quartz, mica, and possibly feldspar

Weathered granite or granitic gneiss

Granite; chiefly quartz, feldspar, and biotite/hornblende

Quartzite

Quartzite (primarily SiO2)

Quartz-rich metamorphic rock (likely quartzite)

Quartzite, dominantly crystalline SiO₂, with probable iron-oxide staining and minor feldspar/mica

Banded Quartzite

Metamorphosed Quartz Sandstone / Quartzite

Quartzite Pebble

Metamorphosed Quartz Sandstone (SiO2)

Granite or granitic gneiss

Quartz–feldspar–mica granitoid; possibly foliated gneiss

Greenstone Porphyry

Porphyritic Metavolcanic Rock

Quartz-rich rock, possibly milky quartz or quartzite

Quartz (SiO₂), potentially quartzite if the grainy texture is rock-wide

Quartzite River Rock (with Quartz Vein)

Quartzite (SiO2)

Likely weathered granite or granitic gneiss fragment

Granite: quartz + feldspar + mica; possibly gneiss if foliation is confirmed

Quartzite

Metamorphosed Quartz Sandstone (SiO2)

Blue-gray quartz-rich rock fragment, likely crushed granite or gneiss

Granite–gneiss aggregate; chiefly quartz (SiO₂), feldspar, and mica/amphibole

Anthracite Coal

Anthracite (Highly Metamorphosed Coal)

Picasso Stone

Metamorphosed Calcium Carbonate (Limestone)

Quartzite (with mineral vein)

Metamorphosed Quartz-rich Sandstone (SiO2)

Small rounded orange-brown stone, likely iron-stained quartzite or sandstone

Indeterminate; probable quartz-rich sandstone/quartzite with iron-oxide staining

Weathered quartz-rich rock, possibly quartzite

Quartzite (predominantly SiO₂), tentative identification

Quartz-rich metamorphic rock, likely quartzite

Quartzite; predominantly quartz (SiO₂), with minor mica and iron-oxide staining

Tumbled gray-green metamorphic rock, likely serpentinite or chlorite schist

Serpentinite/chlorite-rich ultramafic metamorphic rock; commonly dominated by antigorite, lizardite, or chlorite with minor magnetite and talc

Serpentinized ultramafic rock (serpentinite)

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

Marble

Marble (metamorphosed limestone or dolostone), primarily composed of calcite (CaCO3) or dolomite (CaMg(CO3)2)

Riverstone Quartzite (Water-worn Siltstone/Quartzite)

Metamorphosed Quartz-rich Arenite (SiO2)

Quartzite with Calcite Accretion

Metamorphosed Quartz Sandstone (SiO2 with CaCO3 coating)

Rounded quartz-rich pebble, likely quartzite or chert

Quartzite (mostly microcrystalline SiO₂); exact identification requires hardness and acid tests

Serpentinized ultramafic rock (likely serpentinite)

Serpentinite; chiefly serpentine-group minerals (chrysotile, lizardite, antigorite), with olivine/pyroxene relics and possible magnetite