Sedimentary Rock (Possibly Composed Of Various Minerals)

Mixed Rock Collection

Polylithic Geological Specimen Mix

Milky Quartz / Chalcedony

Silicon Dioxide (SiO2)

Sandstone (lithic/greywacke variant)

Clastic sedimentary rock (primarily SiO2 with rock fragments)

Sandstone

Arenite (SiO2 based)

Concretion or Geode (unbroken)

Varied (depending on mineral composition and cementing agent). For quartz-lined geodes, the scientific name of the dominant mineral would be Quartz (SiO2). For calcite-lined geodes, Calcite (CaCO3). Concretions are often composed of cryptocrystalline quartz (chert), calcite, or iron oxides.

Polished Quartz Sphere

Silicon Dioxide (SiO2)

Chalcedony (Common Opal variant or Agate pebble)

Silicon dioxide (SiO2)

Hematite / Ironstone

Iron Oxide (Fe2O3)

Unidentified dark pebble

Undetermined; possibly polished basalt, chert, or iron-rich stone

Quartz Pebble

Silicon Dioxide (SiO2)

Gneiss

Metamorphic Gneiss

Sandstone

Sedimentary Rock (Quartz Arenite)

Sandstone (Water-worn pebble)

Sedimentary Rock (Quartz arenite)

Fossiliferous Shale or Slate with Plant Fossils

Fossil-bearing argillaceous rock

Sandstone (Pebble / Cobble)

Arenite / Sedimentary Rock (composed of quartz and feldspar)

Blue Apatite

Fluorapatite (Ca5(PO4)3F)

Granite boulder

Granite, composed mainly of quartz, alkali feldspar, plagioclase, and minor mica/amphibole

Sandstone (with Iron Staining)

Clastic sedimentary rock (High Silica / Iron Oxide)

River Rock

Sedimentary Rock (various compositions)

Sandstone

Sedimentary Clastic Rock (Quartz Arenite)

Basalt

Fine-grained mafic volcanic rock, chiefly plagioclase feldspar, pyroxene, and commonly olivine

River Stone (possibly Gneiss)

Metamorphic Gneiss

Granite

Phaneritic Felsic Igneous Rock

Sandstone

Arenite (composed primarily of SiO2)

Sandstone (Quartzose)

Arenite (composed primarily of SiO2)

Sandstone (Quartzose Sandstone)

Clastic Sedimentary Rock (composed mostly of SiO2)

Light-colored weathered stone, possibly limestone or quartz-rich rock

Indeterminate; likely calcitic limestone (mostly CaCO₃) or quartz sandstone (SiO₂)

Orange Calcite

Calcium Carbonate (CaCO3)

Bauxite (Laterite Clay)

Bauxite (mixture of Hydrous Aluminum Oxides: Gibbsite Al(OH)3, Boehmite and Diaspore AlO(OH))

Granite

Granite (Felsic Plutonic Rock)

Limestone with Fossil Imprints

Biogenic Limestone (Calcium Carbonate, CaCO3)

Greenschist

Greenschist facies metamorphic rock

Granite Pebble

Granite

Fossiliferous limestone

Bioclastic carbonate rock, chiefly calcite (CaCO₃)

Quartz (Milky/Crystalline)

Silicon Dioxide (SiO2)

Likely weathered quartz-bearing rock (uncertain identification)

Possibly quartz-rich granite or granitic aplite; exact identification requires a clearer, larger image and tests

Marble

Metamorphic rock primarily composed of Calcite (CaCO3)

Sandstone

Arenite (composed primarily of SiO2)

Quartz Geode (likely within Limestone or Dolomite matrix)

Quartz (SiO₂)

Unakite

Epidotized Granite

Indigo Gabbro

Gabbro (MaFIC intrusive rock)

Likely tumbled quartz-rich pebble

Quartz (SiO₂), possibly a weathered quartzite or chalcedony pebble