This Is Not A Rock Or Mineral

Brecciated jasper, possibly rainforest jasper or brecciated rhyolite

Brecciated microcrystalline quartz (SiO₂), commonly called jasper; the green portions may contain epidote, chlorite, or iron-bearing silicates, while red-brown areas are typically hematite or other iron oxides

Bauxite Ore

Hydrated aluminum oxides (e.g., Gibbsite Al(OH)3, Boehmite ̲̲̲̲AlOOH, Diaspore ̲̲̲̲AlOOH)

Quartz (Druzy) in host rock

SiO₂ (Silicon Dioxide) as Quartz, with unspecified host rock components (likely silicates and iron oxides)

Weathered porphyritic basalt

Basalt, likely plagioclase-phyric basalt; primarily a fine-grained aggregate of plagioclase feldspar, clinopyroxene, and possibly olivine or iron-titanium oxides

Northern Shoveler Duck (Note: This is a biological specimen, not a rock)

Spatula clypeata

Amber

Fossilized Tree Resin (Amorphous Hydrocarbon)

Nephrite Jade

Nephrite

Copper Ore / Altered Granodiorite

Cupriferous rock with silicate gangue

Granite

Intrusive Igneous Rock

Likely banded gneiss

Quartz–feldspar–mica gneiss (tentative visual identification)

Angular gray rock fragments

Unidentified fine-grained rock; the image does not show diagnostic features sufficient for a specific identification

Basalt with Quartz Vein

Mafic volcanic rock with hydrothermal SiO2 filling

Granite (weathered cobble)

Granite; chiefly quartz, feldspar, and mica/amphibole

Granite pebble

Granite, chiefly quartz, feldspar, and mica

Likely granite pebble

Granite, a quartz–feldspar–mica intrusive igneous rock

Rock Specimen

Unclassified rock specimen

Crushed stone aggregate

Mixed lithic aggregate; individual fragments cannot be identified from the image

Small red-brown mineral or rock fragment

Unidentified; possibly iron-oxide-rich jasper, garnet, or weathered sulfide

Likely serpentinite (green serpentine rock)

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

Rough garnet-bearing rock, likely almandine garnet in matrix

Almandine garnet, Fe₃Al₂(SiO₄)₃; exact host rock cannot be determined from the image

Gravel / Crushed Stone

Aggregate (mixed mineral rock fragments)

Gneiss (rounded cobble)

Quartz–feldspar–mica gneiss; exact mineral proportions cannot be determined from the image

Milky Quartz Pebble with Iron Inclusions

Silicon Dioxide (SiO2)

Rounded granitic gneiss pebble

Quartz–feldspar–biotite gneiss (tentative; exact identification requires closer inspection)

Red Sandstone

Clastic Sandstone (typically Quartz-rich with Iron Oxide)

Possibly garnet-bearing rock fragment

Unidentified reddish-brown mineral or rock; the image is insufficient for a reliable species identification.

Coarse-grained gray metamorphic rock, likely gneiss

Biotite–quartz–feldspar gneiss (probable)

Sandstone

Arenite

Druzy Quartz on Limestone

Silicon Dioxide (SiO2) on Calcium Carbonate (CaCO3)

Greenstone (likely altered mafic rock)

Chlorite- and amphibole-bearing metabasalt; exact identification requires testing

Sedimentary Rock (Limestone or Siltstone pebble)

Sedimentary rock fragment

Basalt with Quartz Vein

Extrusive Igneous Rock / Volcanic Rock

River Rock

Sedimentary clast

Geode (Quartz / Chalcedony Geode)

SiO2 (Silicon Dioxide)

Likely tumbled greenstone (identity uncertain)

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

Granite Pebbles

Granite (composed primarily of Quartz SiO2, Feldspar (KAlSi3O8 – NaAlSi3O8 – CaAl2Si2O8), and Mica)

Quartz Geode

Silicon Dioxide (SiO2)

Vesicular Basalt

Vesicular Basalt

Druzy quartz on matrix

Quartz (SiO₂), likely microcrystalline-to-fine crystalline drusy quartz

Smooth gray pebbles

Unidentified rounded rock fragments; composition cannot be determined from the image

Quartz River Pebble

Silicon Dioxide (SiO2)

Sandstone

Clastic sedimentary rock (primarily SiO2)