Rock (Likely Sedimentary)

Iron-rich weathered rock, likely limonite/goethite-bearing laterite

Limonite (variable hydrated iron oxides; chiefly goethite, α-FeO(OH))

Weathered mafic rock, likely basalt or greenstone

Fine-grained basaltic rock; possibly altered basalt (metabasalt/greenstone)

Shale

Lutaceous sedimentary rock

Sandstone

Arenite

Quartz-rich metamorphic rock, likely mica schist

Mica schist; chiefly quartz (SiO₂) with biotite/muscovite mica and possible feldspar

Basalt with Quartz Veins

Aphanitic Mafic Igneous Rock (primarily Plagioclase and Pyroxene) with SiO2 inclusions

Quartz Vein in Mica Schist

Quartz (SiO2) with Muscovite/Biotite Schist

Quartzite Cobble

Metamorphic Quartzite (SiO2)

Quartz (likely Milky Quartz or Chalcedony)

Quartz (SiO2 - Silicon Dioxide)

Weathered basaltic cobble

Altered basalt, predominantly plagioclase and pyroxene

Pyrite

Iron Sulfide (FeS2)

Chrysocolla-bearing copper ore

Chrysocolla (hydrated copper phyllosilicate), likely with malachite, quartz, and iron oxides

Weathered granite or granitic gneiss pebble

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

Quartz

Silicon Dioxide (SiO₂)

Likely polished bronzite or serpentine-rich rock

Probable bronzite, an iron-bearing orthopyroxene (Mg,Fe)SiO₃; exact identification requires testing

Granite Pebble

Granite (Phaneritic Igneous Rock)

Pumice or Vesicular Basalt/Scoria (water-worn)

Vesicular volcanic rock

Weathered quartz-rich rock, likely granite or granitic gneiss

Granite–gneiss assemblage; mainly quartz (SiO₂), feldspar, and minor mica/amphibole

Quartz-bearing volcanic rock, likely vesicular basalt

Basalt with secondary quartz (SiO₂) and possible zeolite/chalcedony infill

Quartz Druzy on Matrix (likely Agate or Jasper)

Silicon Dioxide (SiO2) with various mineral inclusions

Vesicular Basalt

Basalt (Mafic Extrusive Igneous Rock)

Quartz pebble

Silicon dioxide (SiO2)

Dark fine-grained river pebble, likely basalt or diabase

Basaltic rock; chiefly plagioclase feldspar and pyroxene, with possible magnetite

Likely tumbled dark volcanic rock

Probably basalt or basaltic andesite; exact identification is uncertain from the image

Amygdaloidal Basalt

Amygdaloidal Basalt (Mafic Volcanic Rock)

Likely weathered basalt or iron-rich volcanic rock

Basalt; primarily plagioclase feldspar, pyroxene, and possibly olivine with iron-oxide alteration

Shale

Shale (clastic sedimentary rock composed of silt and clay-sized particles)

Shale

Fissile mudstone (Shale)

Quartz Vein / Milky Quartz

Silicon Dioxide (SiO2)

Shale

Argillaceous sedimentary rock

Glacial Cobble (likely Granitic or Gneissic)

Granite/Gneiss Glacial Erratic

Granite

Phaneritic plutonic rock (SiO2-rich)

Granite

Granite (Phaneritic intrusive igneous rock)

Granite fragment

Phaneritic Igneous Rock (Granitic composition)

Small dark volcanic rock, likely basalt

Basalt; chiefly plagioclase feldspar, clinopyroxene, and minor olivine or iron-titanium oxides

Limestone with Fossil Inclusion

Calcium Carbonate (CaCO3) - Bioclastic Limestone

Granite (with alteration)

Granite (Felsic intrusive igneous rock)

Quartz Vein in Host Rock

Silicon Dioxide (SiO2) in Slate/Schist

Serpentinite (Commonly known as Serpentine)

Antigorite, Lizardite, or Chrysotile [(Mg,Fe)3Si2O5(OH)4]

Chalcedony (Agate Nodules)

Silicon Dioxide (SiO2)

Quartz (specifically Citrine or Yellow Quartz)

Silicon Dioxide (SiO2)

Small vesicular volcanic rock, likely scoria

Scoria; predominantly basaltic to andesitic volcanic rock