Not A Rock Or Mineral (Anthropogenic Material)

Sandstone

Arenite

Sandstone

Sedimentary Rock (Quartz arenite or arkose)

Limonite-stained quartz vein in host rock

Quartz (SiO₂) with iron-oxide/hydroxide staining, commonly goethite and limonite

Unidentified dark, flat specimen

Indeterminate; image resolution is insufficient for mineral identification

Quartz

Silicon Dioxide (SiO2)

Red jasper (possible polished jasper pebble)

Jasper, an opaque variety of microcrystalline quartz (SiO₂)

Weathered granite or granitic gneiss

Granite/granitic gneiss, composed mainly of quartz, feldspar, and mica

Limestone or Sandstone Cobble

Sedimentary rock (Calcium carbonate or Quartz based)

Sandstone (Tumbled / Rounded)

Sedimentary Rock (Quartz arenite)

Uncertain pale green-gray mineral/rock fragment

Possibly serpentine-bearing rock or greenstone; exact identification requires testing

Sandstone

Sandstone (composed predominantly of SiO2)

Mica-rich schist (likely muscovite schist)

Muscovite–quartz schist; chiefly muscovite mica, quartz, and minor feldspar/biotite

Sandstone pebble

Sandstone (siliciclastic sedimentary rock)

Quartz Pebble

Silicon Dioxide (SiO2)

Sandstone (Ferruginous)

Arenite (primarily SiO2 with iron oxide cement)

Yellow serpentine (likely serpentine-rich rock)

Serpentinite; chiefly serpentine-group minerals, such as antigorite, lizardite, and chrysotile

Sandstone

Arenite (SiO2 primarily)

Sandstone (Ferruginous)

Arenite with Iron Oxide matrix

Sandstone Pebble

Sedimentary Rock (Quartzose Sandstone)

Sandstone (lithic/quartz variant)

Clastic sedimentary rock (SiO2 predominant)

Sandstone

Arenite (primarily SiO2)

Sandstone (lithic wacke/conglomerate mix)

Clastic Sedimentary Rock (SiO2 with lithic fragments)

Fire Opal (in matrix)

Hydrated Silica (SiO2·nH2O)

Shale

Laminated Mudstone

Sandstone

Arenite (SiO2 based)

Sandstone

Arenite

Sandstone

Arenite (composed primarily of SiO2)

Blue-green copper mineral specimen, likely chrysocolla with malachite and quartz

Chrysocolla (hydrated copper aluminum silicate; approximate formula (Cu,Al)₂H₂Si₂O₅(OH)₄·nH₂O), possibly mixed with malachite (Cu₂CO₃(OH)₂) and quartz

Serpentinite (likely veined variety)

Serpentinite; chiefly serpentine-group minerals (antigorite, lizardite, chrysotile), commonly with magnetite and carbonate veins

Likely weathered granite or granitic gneiss

Granite: quartz + feldspar + mica; possibly gneiss if the faint texture reflects foliation

Sandstone

Arenite (SiO2 based)

Gravel / Limestone Fragment

Calcium Carbonate (CaCO3) / Fine-grained Sedimentary Rock

Dark igneous rock, likely basalt or diabase, with a second purplish specimen

Basalt/diabase; exact identification is uncertain from the photograph

Dark, iron-stained rock; exact identification uncertain

Possibly a fine-grained mafic igneous rock (basalt or diabase); image alone is insufficient for a reliable species-level identification

Quartz Geode

Silicon Dioxide (SiO2)

Small dark mineral/rock fragment

Indeterminate; possibly biotite-rich schist, graphite, or metallic sulfide

Sandstone

Clastic sedimentary rock

Red jasper (likely polished/tumbled)

Jasper, an opaque microcrystalline variety of quartz/chalcedony (SiO₂), colored red by iron oxides

Likely dyed or painted stone

Unidentified natural rock; vivid purple, orange, and pink coloration appears to be a surface coating or pigment, so the underlying rock cannot be reliably identified from the image.

Sandstone

Sedimentary Rock (Quartz arenite)

Tumbled orange-and-white chalcedony/agate

Microcrystalline quartz (SiO₂), likely iron-stained chalcedony or carnelian-bearing agate

Sandstone with Quarzite clasts

Arenite (SiO2 based)