Sedimentary Rock (Altered)

Epidote in Quartz

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

Banded Jasper (possibly "Picture Jasper")

Jasper (a microcrystalline variety of Quartz / Silicon Dioxide - SiO2)

Quartz (in matrix)

Quartz (SiO₂)

Jasper and Basalt Mix (Dark Chert/Basalt River Pebble)

Silicon Dioxide (SiO2) or Mafic extrusive igneous rock

Banded Gneiss (Variety of Gneiss)

Gneiss (specifically, a variety exhibiting prominent banding; mineral composition can vary, but often contains quartz, feldspar, mica, and amphibole)

Quartz (possibly milky quartz)

Quartz (Silica; SiO₂)

Aquamarine and clear quartz

Aquamarine (Be3Al2Si6O18), Quartz (SiO2)

Clear Quartz (beads in a bracelet)

Quartz (SiO2)

Carnelian

Chalcedony (cryptocrystalline quartz), SiO2

Pyrite

Pyrite (FeS2)

Micaceous Rock (likely Muscovite Schist/Gneiss or a Muscovite-rich Specimen)

Predominantly Muscovite (KAl2(AlSi3O10)(F,OH)2), often found in rocks like Muscovite Schist or Muscovite Gneiss.

Dyed Agate / Painted Stone

Silicon Dioxide (SiO2) with artificial pigment

Jasper (Milky/Cream Variety)

Silicon Dioxide (SiO2) - variety of Chalcedony

River Cobble (Gneiss/Migmatite)

Gneissic Metamorphic Rock (composed mainly of Quartz, Feldspar, and Biotite)

Calcite

Calcite (CaCO₃, Calcium Carbonate)

Gneiss (specifically a Granitic Gneiss specimen)

Gneiss (high-grade metamorphic rock primarily composed of Quartz, Feldspar, and Biotite/Amphibole)

Quartz

Silicon Dioxide (SiO2)

Zebra Rock (Zebra Stone / Ribbon Stone)

Siltstone with Ferruginous Banding (Primarily Quartz, Kaolinite, and Hematite)

Marble

Marbles are primarily composed of calcite (calcium carbonate, CaCO3) or dolomite (calcium magnesium carbonate, CaMg(CO3)2).

Diorite (possibly fine-grained variety or a related intermediate intrusive rock like a felsic gabbro or a dark granodiorite)

Diorite (Igneous rock, intrusive, intermediate composition)

River Cobble (likely Basalt or Chert)

Siliceous River Rock / Microcrystalline Quartz / Mafic Igneous

Chalcedony (Banded/Mottled Variety)

Chalcedony (a cryptocrystalline variety of Quartz, SiO2)

Quartzite

Quartzite (SiO2)

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).

Quartz with Iron Stains

Quartz (SiO2) with iron oxide/hydroxide staining

Banded Gneiss

Gneiss (pronounced "nice")

Herkimer Diamond in Matrix

Quartz (SiO2) in Dolostone (CaMg(CO3)2)

Quartz

SiO₂ (Silicon Dioxide)

Agate

Agate (a variety of Chalcedony, SiO2)

Quartz

Quartz (SiO2, Silicon Dioxide)

Ocean Jasper

Silicon Dioxide (SiO2) with various inclusions

Bivalve Shell (Fossil or Contemporary)

Class Bivalvie (various genera and species of clams, cockles, etc.)

Limonite (Iron Ore)

Hydrous Iron Oxide (goethite, lepidocrocite)

Kyanite

Kyanite (Al2SiO5)

Note: Image shows a biological specimen (Rat), not a rock. Representative geological equivalent: Galena (due to lead-grey colors in fur).

Galena (PbS)

Quartz

Quartz (Silicon Dioxide, SiO2)

Quartz

Silicon dioxide (SiO₂)

River Stone (likely Basalt or Chert)

Silicon Dioxide (SiO2) for chert or Mafic Extrusive Rock for basalt

Banded Gneiss

Gneiss (variable mineral composition)

Blue Quartz

Quartz (SiO2) with inclusions

Quartz (likely macrocrystalline variety)

Quartz (SiO₂)

Quartz

Silicon Dioxide (SiO2)