Antropogenic (Man Made)

Granite

Phaneritic Felsic Igneous Rock

Dark mafic rock, likely basalt

Basalt; chiefly plagioclase feldspar, pyroxene, and commonly olivine or iron-titanium oxides

Greenstone (likely serpentinite or greenstone pebble)

Serpentinite-rich ultramafic rock; commonly dominated by serpentine-group minerals, with possible chlorite, actinolite, or magnetite

Dark fine-grained rock, likely basalt

Basalt; chiefly plagioclase feldspar and pyroxene, commonly with olivine and iron oxides

Black basalt fragment

Basalt; fine-grained mafic volcanic rock, chiefly plagioclase and pyroxene with possible olivine

Apatite

Ca5(PO4)3(F,Cl,OH)

Limestone Gravel

Sedimentary Calcium Carbonate (CaCO3)

Granite

Phaneritic plutonic rock (Quartz-Alkali Feldspar-Plagioclase)

Granite

Felsic Plutonic Rock (primarily SiO2)

Granite

Phaneritic plutonic rock (Quartz + Feldspar + Mica)

Granite

Phaneritic Igneous Rock (primarily Quartz, Feldspar, Mica)

Calcite

Calcite (CaCO3)

Polished white chalcedony or milky quartz pebble

Chalcedony, microcrystalline quartz (SiO₂), possibly with iron-oxide staining or a minor mineral inclusion

Likely quartz-rich rock or weathered granite fragment

Granite-like quartz–feldspar aggregate; exact identification requires testing

Dark mafic rock, likely basalt

Basalt (fine-grained assemblage chiefly plagioclase and pyroxene, commonly with olivine and iron oxides)

Dark igneous rock, likely basalt

Basalt; chiefly plagioclase feldspar, pyroxene, and possibly olivine

Pink Granite (River Pebble)

Felsic intrusive igneous rock (consisting of Quartz, Orthoclase Feldspar, and Plagioclase)

Granite

Granite (Felsic Plutonic Rock)

Limestone

Calcium Carbonate (CaCO3)

Granite

Granitoid

Sandstone

Arenite (typically composed of SiO2)

Limestone

Calcium Carbonate (CaCO3)

Likely basalt or vesicular volcanic rock

Basalt, possibly scoriaceous basalt; exact identification is uncertain from the photograph

Red Jasper

Silicon dioxide (Microcrystalline Quartz, SiO2)

Granite

Granite (felsic intrusive igneous rock)

Granite

Granite (composed primarily of Quartz, Feldspar, and Mica/Amphibole)

Blue Apatite

Fluorapatite (Ca5(PO4)3F)

Granite

Phaneritic Igneous Rock (Granite)

Limestone (specifically Travertine or Tufa)

Calcium Carbonate (CaCO3)

Granite

Course-grained intrusive igneous rock

Diabase (also known as Dolerite)

Diabase / Dolerite

Sandstone Pebble

Arenite (primarily SiO2)

Limestone

Calcium Carbonate (CaCO3)

Sandstone (with potential mineral inclusions)

Clastic sedimentary rock (primarily Quartz, SiO2)

Limestone

Calcium Carbonate (CaCO3)

Limestone

Calcium Carbonate (CaCO3)

Granite River Rock

Phaneritic Felsic Igneous Rock (Granite)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Tumbled milky quartz

Quartz (silicon dioxide, SiO₂)

Quartz

Quartz (SiO₂ - Silicon Dioxide)

Lapis Lazuli

A metamorphic rock primarily composed of lazurite (Na,Ca)8[(S,SO4,Cl)2|(Al6Si6O24)], calcite (CaCO3), and pyrite (FeS2).

Rounded basalt pebble

Basalt; primarily plagioclase feldspar, pyroxene, and commonly olivine