Sedimentary Rock (Metamorphosed)

Quartzite

Metamorphosed Quartz Sandstone (SiO2)

Eclogite garnet in matrix

Eclogite (Garnet-Omphacite rock)

Tumbled quartz-rich stone, likely milky quartz

Quartz (SiO₂), possibly iron-stained milky quartz or quartzite

Weathered quartz-rich rock, possibly sandstone or quartzite

Indeterminate; likely quartz sandstone (SiO₂-rich), possibly weakly metamorphosed quartzite

Weathered quartz-rich river cobble, possibly quartzite

Quartzite (mostly microcrystalline SiO₂), tentatively identified

Anthracite Coal

Anthracite (Highly Metamorphosed Coal)

Anthracite Coal

Anthracite (Metamorphosed Bituminous Coal)

Anthracite Coal

Anthracite (Highly Metamorphosed Coal)

Likely serpentine-rich metamorphic rock

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

Likely tumbled quartz-bearing rock or glittery quartz specimen

Quartz, silicon dioxide (SiO₂), possibly included quartz or quartzite

Tumbled reddish-brown stone, possibly jasper or iron-rich quartzite

Uncertain from image; likely microcrystalline quartz (SiO₂) with iron-oxide inclusions

Banded Marble (Egg Carving)

Metamorphosed Limestone (predominantly CaCO3)

Quartzite

Metamorphosed Quartz Sandstone (primarily SiO2)

Likely tumbled greenstone (identity uncertain)

Greenstone: metamorphosed mafic volcanic rock, commonly composed of chlorite, actinolite, and epidote

Weathered quartz-rich rock, likely milky quartz with iron staining

Quartz (SiO₂), possibly quartz vein material or quartzite

Iron-rich quartzite or weathered ironstone

Quartzite dominated by SiO₂, with iron oxides/hydroxides such as hematite and goethite

Coarse-grained granite or granitic gneiss

Granite; primarily quartz, potassium feldspar, plagioclase, and biotite/hornblende

Quartz-rich breccia or quartzite with iron-oxide veining

Microcrystalline to granular SiO₂ (quartz), with hematite/goethite and minor feldspar or mica

Granite or granitic gneiss

Granite; primarily quartz, feldspar, and mica (possibly weakly foliated gneiss)

Anthracite Coal

Anthracite (Highly Metamorphosed Coal)

Picasso Stone

Metamorphosed Calcium Carbonate (Limestone)

Quartzite with Hematite staining

Metamorphosed Quartz-rich sandstone (SiO2)

Tumbled yellow jasper or iron-stained quartzite

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

Quartzite (River Pebble)

Metamorphosed Quartz-rich Sandstone (SiO2)

Weathered quartz-bearing rock, possibly druzy quartz or quartzite

Quartz (SiO₂), likely in a quartz-rich host rock; exact identification is uncertain from the photograph

Rounded quartz-rich river pebble

Likely quartzite or weathered sandstone; exact identification requires testing

Quartz / Quartzite

Silicon Dioxide (SiO2)

Likely amphibolite

Amphibolite, composed mainly of hornblende and plagioclase feldspar

Quartzite

Quartzite (primarily SiO2)

Granite or granitic gneiss

Quartz–feldspar–mica aggregate; possibly banded orthogneiss

Greenstone / Basalt with Amygdule

Amygdaloidal Basalt (altered to Greenstone)

Quartzite Pebble

Metamorphosed Quartz Sandstone (SiO2)

Rounded quartz-rich cobble

Likely quartzite or siliceous sandstone; predominantly microcrystalline SiO₂ with possible feldspar and iron-oxide staining

Weathered igneous rock, likely granite or granitic gneiss

Quartz–feldspar–mica aggregate; exact identification requires a fresh surface or testing

Serpentine-rich altered rock (likely serpentinite)

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

Dark gray veined metamorphic rock

Likely marble or quartzite; exact identification requires hardness and acid tests

Red granite or granitic gneiss fragment

Felsic granitoid, chiefly quartz, potassium feldspar, plagioclase, and biotite/hornblende

Iron-stained quartz-rich rock (possibly ironstone or quartzite)

Quartz-rich silicate rock with iron oxides; exact rock type cannot be confirmed from the image

Likely amphibolite (dark hornblende-rich rock)

Amphibolite, typically composed mainly of hornblende and plagioclase feldspar

Rounded river cobble

Likely quartz-rich sandstone or metamorphosed quartzite; exact identification is uncertain from the photograph

Granite or granitic gneiss boulders

Quartz–feldspar–mica granitoid; possibly banded gneiss

Tumbled green aventurine (probable)

Quartzite dominated by quartz (SiO₂), with green fuchsite mica inclusions