Not A Rock Or Mineral

Quartz-rich rock fragment

Likely quartz vein material, predominantly quartz (SiO₂); identification is tentative from the image

Clear gemstone earring (likely cubic zirconia)

Cubic zirconia (synthetic zirconium dioxide, ZrO₂); identification from the image is uncertain

Serpentinite

Serpentinite, a rock composed mainly of serpentine-group minerals (approximately Mg₃Si₂O₅(OH)₄)

Greenstone (likely serpentine-rich rock)

Serpentinite, composed mainly of serpentine-group minerals

Likely rough green aventurine

Quartz (SiO₂), with green coloration likely from mica or other inclusions

Granite pebble

Granite, a coarse-grained felsic intrusive igneous rock composed mainly of quartz, feldspar, and mica

Polished feldspar-rich granite

Granite, primarily quartz (SiO₂), feldspar, and mica

Quartz-rich rock, possibly vein quartz in host rock

Quartz (SiO₂), with unidentified host-rock minerals

Polished brecciated jasper

Jasper, an opaque microcrystalline variety of chalcedony (SiO₂), with iron-oxide staining

Turquoise (small irregular fragment)

Turquoise, hydrated copper aluminum phosphate: CuAl₆(PO₄)₄(OH)₈·4H₂O

Likely serpentinite

Serpentinite, composed mainly of serpentine-group minerals (e.g., antigorite, lizardite, or chrysotile)

Weathered iron-rich rock, possibly ironstone or altered basalt

Indeterminate; likely ferruginous basalt/ironstone containing hematite-goethite and silicate minerals

Quartz Druzy on Geode Fragment

Silicon Dioxide (SiO2)

Sea stacks and coastal cliffs

Likely basaltic sea stacks (rock type cannot be confirmed from the image)

Greenstone (likely chlorite-rich metamorphic rock)

Chlorite-rich greenschist; commonly composed of chlorite, actinolite, and epidote

Likely sodalite (rough blue specimen)

Sodalite, Na₈(Al₆Si₆O₂₄)Cl₂

Garnet in marble

Likely almandine or pyrope garnet (X₃Y₂(SiO₄)₃) in calcite marble; species cannot be confirmed from the image alone.

Likely rough garnet-bearing rock

Possibly garnetiferous schist or gneiss; identification is uncertain from the photo

Brecciated quartz vein rock

Quartz (SiO₂), with iron-oxide staining and likely feldspar/carbonate gangue

Clear Quartz (Druzy)

Crystalline Silicon Dioxide (SiO2)

Granite (likely weathered, coarse-grained specimen)

Granite; chiefly quartz, feldspar, and mica

Milky quartz-bearing rock

Quartz, silicon dioxide (SiO₂), likely massive quartz with iron-oxide staining

Tumbled greenstone or serpentinite pebble

Likely serpentine-group rock (serpentinite); exact identification is uncertain from the image

Red jasper

Jasper, a microcrystalline variety of quartz (SiO₂), colored mainly by iron oxides

Possibly tumbled dark stone or mineral specimen

Indeterminate from image; possibly black tourmaline, basalt, or another dark silicate

Tumbled jasper pebble

Jasper, an opaque microcrystalline variety of quartz (SiO₂), commonly colored by iron oxides and hydroxides

Granite (likely biotite granite or granodiorite)

Coarse-grained felsic intrusive rock composed mainly of quartz, feldspar, and mica; approximate composition: SiO₂-rich, with variable K-feldspar/plagioclase and biotite.

Likely serpentinite (green serpentine rock)

Serpentinite, composed chiefly of serpentine-group minerals (antigorite, lizardite, and/or chrysotile)

Red granite boulder

Granite, a coarse-grained felsic intrusive igneous rock; commonly quartz + feldspar + mica

Weathered granite cobble

Granite, a coarse-grained felsic intrusive igneous rock

Pink feldspar-rich granite

Granite, composed chiefly of quartz, potassium feldspar, and plagioclase, with minor mica or other minerals

Likely foliated metamorphic rock (schist or gneiss fragment)

Mica schist–gneiss; chiefly quartz, feldspar, and mica

Likely bituminous coal

Coal, predominantly maceral-rich carbonaceous material (composition varies)

Granite (with a dark inclusion or attached fragment)

Granite, mainly quartz, feldspar, and mica; the dark object cannot be identified confidently from the photo.

Fossil bivalve shell

Likely an extinct or modern-like ribbed cockle/scallop; exact genus requires locality and diagnostic hinge features

Drusy quartz on a matrix (tentative)

Quartz, SiO₂, as a fine-grained drusy coating; associated matrix is unclear from the image

Quartz geode or druzy quartz specimen

Quartz, silicon dioxide (SiO₂), likely microcrystalline/drusy quartz coating a host rock

Likely pink granite pebble

Granite, a coarse-grained felsic intrusive rock (typically quartz, feldspar, and mica)

Druzy Quartz on Sandstone

Silicon Dioxide (SiO2) with Quartz Crystals on Clastic Sedimentary Rock

White quartz-rich rock, likely milky quartz or quartzite

Quartz (SiO₂); possibly quartzite, a metamorphosed quartz sandstone

Rough garnet-bearing rock (likely almandine garnet in host rock)

Garnet, probably almandine (Fe₃Al₂(SiO₄)₃), in a garnet-bearing metamorphic matrix

Vesicular basalt (scoriaceous basalt)

Basalt; predominantly plagioclase, clinopyroxene, and olivine with iron oxides