Mineral (Tectosilicate)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Amygdaloidal Basalt with Epidote

Vesicular Basalt with secondary Epidote/Quartz mineral infill

Pink Granite (with Potassic Feldspar and Quartz)

Felsic Intrusive Igneous Rock (Granite)

Granite

Phaneritic Igneous Rock (primarily Quartz, Feldspar, and Mica)

Dark-colored Igneous Rock (likely Basalt or Diabase)

Basalt (extrusive igneous) or Diabase (intrusive igneous)

Quartzite River Rock with Dendrites

Metamorphosed Quartz-rich Sandstone with Manganese Oxide (MnO2) inclusions

Honeycomb Calcite

Calcite (Calcium Carbonate, CaCO3)

Milky Quartz

Silicon Dioxide (SiO2)

Black Sapphire

Corundum (Al2O3 with iron and titanium impurities)

Milky Quartz

Silicon Dioxide (SiO2)

Kimberlite with Diamond

Kimberlite (Diamond formula: C)

Diorite (Polished River Pebble)

Diorite (Intermediate intrusive igneous rock)

Gneiss

Gneiss (Metamorphic rock composed primarily of quartz, feldspar, and mica)

Mica Schist with Quartz

Mica-Quartz Schist (Muscovite subclass)

Diorite

Diorite (plutonic igneous rock)

Shale

Fissile Mudrock (Clay-rich Sedimentary Rock)

Rhodochrosite

Manganese Carbonate (MnCO3)

Blue Apatite

Fluorapatite (Ca5(PO4)3F)

Pink Granite

Phaneritic Felsic Intrusive Igneous Rock

Sandstone

Sandstone (arenite is a more specific geological term for a clean sandstone, while wacke refers to a dirty sandstone with significant matrix)

Strawberry Quartz

Quartz (SiO2) with inclusions of Goethite or Hematite

Azurite-Malachite (often a mixed specimen)

Azurite: Cu3(CO3)2(OH)2; Malachite: Cu2(CO3)(OH)2. The specimen appears to be a natural mixture or intergrowth of these two minerals.

Vesicular Basalt with Secondary Mineral Inclusions

Aphanitic Mafic Igneous Rock (primarily Plagioclase and Pyroxene)

Pyrite

Iron Disulfide (FeS2)

Limonite (Iron Stone/Ocher)

Limonite (FeO(OH)·nH2O)

Chrysocolla on Matrix

Hydrated copper phyllosilicate (Cu,Al)2H2Si2O5(OH)4·nH2O

Greenstone

Greenschist (containing chlorite, epidote, and actinolite)

Limestone with Quartz/Calcite Veins

Sedimentary Limestone (CaCO3 with SiO2 or CaCO3 intrusions)

Geode with Iron-Stained Quartz/Calcite

Silicon Dioxide (SiO2) or Calcium Carbonate (CaCO3) in Sedimentary Matrix

Psilomelane (Black Hematite/Manganese Ore)

Barium Manganese Oxide (Formula: BaMn9O18(OH)4)

Red Sandstone

Arenite (primarily Quartz SiO2 with Hematite Fe2O3 cement)

Red Sandstone

Arenite (primarily composed of SiO2 with Fe2O3 cement)

Chrysocolla

Hydrated copper phyllosilicate, Cu2-xAlx(H2-xSi2O5)(OH)4·n(H2O)

Tumbled Stones (various)

Mixed Silica-based Minerals (primarily Quartz and Chalcedony)

Pearl

Calcium carbonate (CaCO3) + organic conchiolin (Biogenic Mineral)

Rose Quartz

Silicon Dioxide (SiO2) with inclusions of Dumortierite or similar minerals

Dumortierite Quartz

Al7BO3(SiO4)3O3 (Borosilicate mineral/Quartz inclusion)

Amygdaloidal Rhyolite

Amygdaloidal felsic extrusive rock

Tiger's Eye

Tiger's Eye (SiO2 with crocidolite inclusions)

Quartzite

Quartzite (Primary mineral: Quartz, SiO2)

Quartzite (River Cobble)

Quartzite (dominant mineral: Quatrz, SiO2)

Sandstone

Arenite (SiO2 based with mineral cement)