Igneous And Sedimentary

River Stone (Basalt or Siltstone with banding)

Polished Basaltic or Siliciclastic River Cobble

Mixed River Pebbles (including Unakite and Jasper)

Polymineralic geological specimens

Chalcedony (or a variety of Chalcedony, likely Agate or Jasper)

Chalcedony (SiO₂)

River Rocks (Basalt and Sedimentary Stones)

Mafic Igneous Rock (Basalt) and Clastic Sedimentary Rock

Pink Opal / Peruvian Opal

Hydrated amorphous silicon dioxide (SiO2·nH2O)

River Stones (Basalt and Sedimentary Rock)

Basalt (dark specimen) and Siltstone/Mudstone (reddish specimen)

Basalt and Quartz Pebble

Basalt (Igneous) and Quartzite/Quartz (SiO2) pebble

River Rock (Basalt or Sandstone)

Clastic Sedimentary Rock or Extrusive Mafic Igneous Rock

Ruby in Zoisite

Ruby (α-Al2O3) embedded in Zoisite (Ca2Al3(SiO4)3(OH)) with some Hornblende

Basalt or Siltstone Pebbles

Mafic volcanic rock (Basalt) or Indurated Siltstone

River Pebbles (Basalt and Graywacke/Limestone)

Mafic Volcanic Rock / Impure Sandstone

River Stone (Basalt or Siltstone)

Mafic Volcanic Rock or Clastic Sedimentary Rock

Gneiss

Gneiss (High-grade metamorphic rock)

Pebble (Likely Basalt or Siltstone)

Clastic sedimentary rock or mafic volcanic rock

Banded River Cobble with Mafic Dike

Hydrothermally altered Graywacke or Sandstone with Mafic Intrusion

Wishing Stone (Basalt or Mudstone with Quartz/Calcite Veins)

Hydrothermally veined Basalt (SiO2/CaCO3 intrusions)

Granite (phaneritic background) with Limestone/Calcite carving

Felsic Igneous Plutonic Rock (background) / Calcium Carbonate (CaCO3) (carving)

River Rock (Basalt/Greywacke pebbles)

Fluvial gravel primarily composed of Mafic Volcanic Rock (Basalt) or Lithic Sandstone (Greywacke)

River Pebbles (Tumbled Quartz and Basalt)

Silicon Dioxide (SiO2) for white quartz; Mafic Volcanic Rock for basalt

Jasper and Basalt Pebble

Polymineralic lithic pebble

Wishing Stone (Basalt or Siltstone with Quartz/Calcite Vein)

Basalt (SiO2+MgO+FeO) or Siltstone with a Quartz (SiO2) or Calcite (CaCO3) vein

Wishing Stone (Basalt or Chert with Quartz Veins)

Basalt or microcrystalline Quartz (Chert) with localized hydrothermal Quartz (SiO2) veining

Epidote in Quartz

Quartz with Epidote inclusions (SiO2 with Ca2(Al,Fe)3(SiO4)3(OH) inclusions)

Banded Rock (likely Quartz-rich)

Uncertain, likely a Metamorphic Rock (e.g., Gneiss or Schist) with prominent Quartz and other minerals

Garnet (Red Garnet)

Garnet Group. The red varieties seen in jewelry are typically Almandine (Fe3Al2(SiO4)3), Pyrope (Mg3Al2(SiO4)3), or a mix of the two (pyrope-almandine series).

Apatite

Apatite group mineral (e.g., Fluorapatite - Ca5(PO4)3F, Chlorapatite - Ca5(PO4)3Cl, Hydroxylapatite - Ca5(PO4)3(OH))

Carnelian

Chalcedony (cryptocrystalline quartz), SiO2

Banded Gneiss

Gneiss (variable mineral composition)

Epidote (or Epidote-rich rock)

Epidote. Mineral formula: Ca2(Al,Fe)3(SiO4)3(OH).

Banded River Rock / Gneiss (highly weathered)

Gneiss

Red Chalcedony (likely dyed)

Chalcedony (a variety of Quartz), SiO2

Quartz / Limestone Gravel

SiO2 (Silicon Dioxide) and CaCO3 (Calcium Carbonate)

Mixed collection of natural stones

Several unidentified lithologies, likely including basalt, granite, quartzite, sandstone, and weathered metamorphic rocks

Banded Gneiss

Gneiss (pronounced "nice")

Gneiss

Gneiss (a type of metamorphic rock)

Gneiss

Feldspathic biotite gneiss; a high-grade metamorphic rock composed mainly of quartz, feldspar, and mica

Obsidian and Green Calcite

Volcanic Glass and Calcium Carbonate (CaCO3)

River Cobbles (Basalt, Quartzite, and Sandstone mix)

Fluvial detritus (primarily SiO2, Plagioclase, and Pyroxene mix)

Mixed Crushed Stone

Aggregate (varied mineral composition)

River Rock (likely Basalt or Greywacke)

Basalt or Lithic Sandstone

Quartz with Basalt inclusion

Silicon Dioxide (SiO2) with mafic silicate rock

Painted Garden Rock (likely Granite or Limestone base)

Silicon Dioxide (SiO2) / Calcium Carbonate (CaCO3) based substrate with Acrylic/Enamel pigments