Mineral, Possibly Rock Fragment Containing A Mineral

Not a geological specimen

N/A (man-made object)

Amygdaloidal Basalt

Basalt with secondary amygdule minerals (likely Epidote or Chlorite)

Sandstone (likely Quartzose Sandstone)

Arenite (SiO2 based)

Biotite-bearing granite

Granite, composed mainly of quartz (SiO₂), potassium feldspar, plagioclase, and biotite mica

Smoky Quartz

Smoky Quartz (SiO2: Silicon Dioxide)

Jasper or Chert

Silicon Dioxide (SiO2)

Tourmalinated Quartz

Silicon Dioxide with Tourmaline inclusions (SiO2 + Na(Fe3Al6)(Al5Si6O18)(BO33)(OH4))

Mica-rich metamorphic rock, likely schist

Muscovite–biotite schist, possibly with quartz and feldspar

Moss Agate

Silicon Dioxide (SiO2) with inclusions

Rose Quartz

Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese

Amethyst Quartz

Silicon Dioxide (SiO2) with iron impurities

Porphyritic Igneous Rock / Granite or Rhyolite Porphyry

Porphyritic intrusive/extrusive igneous rock

Granite

Intrusive Igneous Rock (Felsic)

Conglomerate

Conglomerate (clastic sedimentary rock)

Granite

Intrusive Igneous Rock

River Stone / Pebble

Clastic Sediment (composed largely of Quartz, Feldspar, and various rock fragments)

Chert or chalcedony fragment (possibly agate)

Microcrystalline quartz, SiO₂

Conglomerate

Conglomerate (clastic sedimentary rock)

Sandstone (Greywacke)

Arenite / Lithic Wacke (SiO2 predominant)

Granite

Felsic intrusive igneous rock

Sandstone

Arenite (primarily SiO2)

Mica Schist with Quartz

Schist containing Muscovite and Quartz

Weathered basalt (likely vesicular basalt)

Basalt; primarily plagioclase feldspar, pyroxene, and commonly olivine

Rock Fragment with Calcite/Quartz Vein

Polymictic Rock Fragment (SiO2 / CaCO3)

Tumbled limestone or marble fragment

Calcite (CaCO₃), likely marble; possibly compact limestone

Sandstone (lithic wacke/arenite)

Clastic sedimentary rock (primarily SiO2)

Likely weathered mica-rich rock fragment

Probable schist, composed mainly of quartz, feldspar, and mica

Granite

Felsic intrusive igneous rock

Turquoise

Hydrated phosphate of copper and aluminium (CuAl6(PO4)4(OH)8·4H2O)

Weathered chert or silicified limestone nodule

Microcrystalline quartz (SiO₂), possibly replacing limestone; exact identification requires testing

Dendritic Agate

Silicon Dioxide (SiO2) with Manganese/Iron inclusions

Quartz Geode Fragment

Silicon Dioxide (SiO2)

Sandstone (Weathered Fragment)

Clastic Sedimentary Rock

Blue cabochon gemstone, likely sapphire

Corundum (Al₂O₃), blue variety colored mainly by iron and titanium

Weathered iron-rich sandstone or conglomeratic sedimentary cobble

Ferruginous sandstone, possibly polymictic conglomerate

Amygdaloidal Basalt

Amygdaloidal Basalt

Pegmatite

Pegmatitic Granite

Sandstone (likely Ferruginous)

Arenite with Iron Oxide cement

Quartz (Small Fragment)

Silicon Dioxide (SiO2)

Red jasper-bearing breccia (probable)

Microcrystalline quartz (SiO₂) with iron-oxide coloration, in a brecciated host

Quartz (Gravel Fragment)

Silicon Dioxide (SiO2)

Limestone Gravel

Calcium Carbonate (CaCO3)