Mineraloid (Anthropogenic)

Polished serpentine-rich stone

Serpentinite, primarily serpentine-group minerals (antigorite, lizardite, or chrysotile)

Blue sodalite-bearing rock (likely sodalite rough)

Sodalite, Na₈(Al₆Si₆O₂₄)Cl₂, possibly in syenite or lapis-lazuli-like matrix

Weathered river pebble, likely quartz-rich sandstone or quartzite

Indeterminate; probable quartz (SiO₂)-rich sandstone/quartzite with iron-oxide staining

Likely serpentinite or serpentinized ultramafic rock

Serpentinite; chiefly serpentine-group minerals (Mg₃Si₂O₅(OH)₄), possibly with magnetite and minor olivine/pyroxene

Rounded greenstone cobble

Likely greenschist or altered basalt; composition commonly chlorite, epidote, actinolite, albite, and quartz

Granite

Intrusive Igneous Rock

Polished orbicular gabbro tower

Gabbro, likely orbicular/pegmatitic variety; mainly plagioclase feldspar and pyroxene, with possible amphibole, olivine, and magnetite

Brown chert or flint pebble

Microcrystalline quartz (SiO₂), commonly with chalcedony and iron-oxide staining

Dark metamorphic rock, likely biotite schist or hornblende-bearing gneiss

Probable mica schist/amphibolite; composition may include biotite, amphibole, quartz, feldspar, and iron oxides

Tumbled quartz-rich pebble

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

Gold-bearing pyrite-rich rock (iron pyrite)

Pyrite, FeS₂, likely in a quartz- or sulfide-rich matrix

Weathered quartz-rich rock, likely quartzite or milky-quartz vein material

Quartzite (dominantly SiO₂), possibly quartz-vein breccia with iron-oxide staining

Iron-stained quartz-rich rock, likely pegmatite or quartz vein fragment

Quartz (SiO₂) with feldspar, mica, and iron-oxide/hydroxide staining; possibly weathered granite pegmatite

Red Granite

Phaneritic Felsic Intrusive Igneous Rock (primarily K-feldspar, Quartz, and Biotite)

Red Granite

Phaneritic Plutonic Rock (High Potassium Feldspar)

Rhyolite

Extrusive Felsic Igneous Rock

Weathered quartz-rich rock, possibly chert or quartzite

Indeterminate; likely microcrystalline quartz (SiO₂), possibly quartzite or chert

Polished dark green stone (likely serpentine or greenstone)

Serpentine-group mineral aggregate, commonly antigorite/lizardite; identification is uncertain from the image

Sapphire

Corundum (Al2O3)

Weathered conglomeratic or breccia cobble

Lithified polymictic conglomerate/breccia, likely iron-stained siliciclastic rock

Scoria (vesicular volcanic rock)

Scoria; mafic to intermediate vesicular volcanic rock, commonly basaltic or andesitic

Likely serpentine-rich metamorphic rock

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

Basalt

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

Weathered sandstone fragment

Quartz-rich clastic sandstone, possibly arkose or lithic sandstone

Weathered iron-rich rock, possibly limonite-bearing sandstone or ironstone

Limonite/goethite-rich ferruginous sandstone; composition uncertain from the photograph

Weathered sedimentary rock, possibly sandstone

Indeterminate clastic sediment; probable quartz-rich sandstone

Weathered iron-rich rock, possibly limonite-bearing sandstone

Limonite/goethite-bearing sandstone or ferruginous conglomeratic rock

Likely weathered basalt or andesite fragment

Fine-grained mafic to intermediate volcanic rock; commonly plagioclase ± pyroxene ± olivine

Polished greenstone pebble (likely epidote-bearing stone)

Epidote–chlorite amphibolite or altered basalt; composition likely epidote, chlorite, amphibole/pyroxene, and iron oxides

Iron-rich meteorite candidate

Undetermined stony-iron or iron meteorite; possible weathered iron meteorite

Polished pink gemstone, likely dyed quartz or chalcedony

Uncertain from image; possibilities include dyed quartz (SiO₂) or chalcedony (microcrystalline SiO₂)

Greenstone (likely altered basalt or serpentinite)

Chlorite–epidote amphibolite/greenschist or serpentinite; exact identification requires testing

Weathered, rounded polymictic pebble (likely volcanic or metamorphic rock)

Indeterminate; possibly altered basalt, greenstone, or epidote-bearing metamorphic rock

Small rounded pebble

Indeterminate lithic grain; likely weathered sandstone, iron-stained quartz-rich rock, or a concretion

Quartz-rich metamorphic rock (probable quartzite)

Quartzite; predominantly crystalline SiO₂, with possible mica and iron-oxide impurities

Weathered mafic rock, likely basalt

Basalt; predominantly plagioclase feldspar and pyroxene, possibly olivine and iron oxides

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

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

Granite

Granite (Phaneritic igneous rock)

Granite

Phaneritic Igneous Rock (composed primarily of Quartz SiO2, Alkali Feldspar, and Plagioclase)

Dark mafic rock, possibly basalt or altered gabbro

Basaltic rock; commonly composed of plagioclase feldspar, pyroxene, and possibly olivine or iron oxides

Weathered sandstone boulder

Sandstone, chiefly quartz (SiO₂) with feldspar and iron-oxide cement

Polished brecciated jasper or iron-rich agate

Microcrystalline quartz (SiO₂), with hematite/goethite and possible iron oxides