Basalt

Amethyst

SiO2 (Silicon Dioxide) - Purple variety of Quartz

Native Copper

Native Copper (Cu)

Amethyst

Silicon Dioxide with Iron impurities (SiO2)

Amethyst

SiO2 (Silicon Dioxide) - a variety of Quartz

Larimar

Blue Pectolite (NaCa2Si3O8(OH))

Granite

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

Amethyst

Silicon dioxide with iron impurities (SiO2)

Sunstone

Oligoclase (a plagioclase feldspar variant), (Na,Ca)(Al,Si)4O8

Labradorite (tumbled)

Labradorite (a plagioclase feldspar mineral between anorthite and albite; chemical formula: (Ca,Na)(Si,Al)4O8)

Prehnite

Prehnite, Ca2Al2Si3O10(OH)2

Michigan Float Copper

Native Copper (Cu)

Peridot (likely, based on color and appearance)

Olivine group mineral, specifically (Mg,Fe)2SiO4 (Forsterite-Fayalite solid solution series)

Chinese Writing Stone

Porphyritic Basalt or Porphyritic Andesite with Feldspar phenocrysts (SiO2-rich Silicates)

Red Scoria (Lava Rock)

Scoria (Extrusive Igneous Rock / Mafic composition)

Amethyst (Druzy Cluster)

Silicon Dioxide (SiO2) with Fe3+ impurities

Banded Agate (specifically Lake Superior Agate type)

Silicon Dioxide (SiO2) - Microcrystalline Chalcedony

Nephrite Jade

Nephrite (a variety of the mineral actinolite within the amphibole group); Chemical Formula: Ca2(Mg,Fe)5Si8O22(OH)2

Laterite (iron-rich nodule, possibly Bauxite as a subtype)

Laterite (composed of various minerals including goethite, hematite, gibbsite, etc.)

Pearl (with Peridot)

Calcium carbonate (CaCO3) + Conchiolin; Peridot: Magnesium iron silicate (Mg, Fe)2SiO4

Peridot

Olivine (specific variety: gem-quality forsterite), (Mg,Fe)2SiO4

River Cobble (Basaltic/Andesitic)

Mafic Igneous Porphyritic Rock

Amethyst (variety of Quartz)

SiO2 (Silicon Dioxide)

Chalcedony (Botryoidal or Agate nodule)

Silicon Dioxide (SiO2)

Amethyst

Amethyst is a variety of Quartz (SiO₂)

Quartz Geode (partially formed/chalcedony with iron staining)

Quartz (SiO2) with Chalcedony (cryptocrystalline quartz) and likely Iron Oxides/Hydroxides

Porphyry (likely Porphyritic Andesite or Basalt)

Porphyritic Igneous Rock

Porphyry (specifically Porphyritic Basalt or Andesite)

Porphyritic extrusive igneous rock (Mg,Fe)2SiO4 (Olivine inclusions/Plagioclase Feldspar)

Greenstone (Epidote/Chlorite-rich Metabasalt)

Greenschist / Epidosite (Ca2(Al,Fe)3(SiO4)3(OH))

Amethyst

SiO2 (Silicon Dioxide)

Amethyst (variety of Quartz)

SiO2 (Silicon Dioxide) with trace iron impurities

Jade (likely Nephrite or Jadeite)

Nephrite (a variety of actinolite, Ca2(Mg,Fe)5Si8O22(OH)2) or Jadeite (NaAlSi2O6)

Carnelian

Carnelian (a variety of Chalcedony, SiO2)

Hypersthene (or Enstatite/Ferrosilite)

Orthopyroxene series (Mg,Fe)SiO3 - specifically, historically hypersthene (intermediate member) now referred to as Enstatite (Mg-rich) or Ferrosilite (Fe-rich)

River Cobble (Conglomerate context)

Unconsolidated Fluvial Alluvium (comprised of various lithologies like Quartzite, Granite, or Basalt)

Sandstone (likely with Borings or Vesicular Basalt)

Clastic Sedimentary Rock (Sandstone)

River Cobble (likely Basalt or Rhyolite)

Extrusive Igneous Rock (Mafic or Intermediate)

Peridot (Olivine)

Olivine ((Mg,Fe)2SiO4)

Snowflake Obsidian (or similar porphyritic volcanic rock)

Obsidian with Spherulites (if glassy), or Porphyritic Rhyolite/Andesite (if crystalline groundmass)

Jasper, Agate, Quartz Mix (Polished Beads)

SiO₂ (Silicon Dioxide) for Quartz. Jasper and Agate are cryptocrystalline varieties of Quartz.

Prehnite with Epidote inclusions

Prehnite: Ca2Al(AlSi3O10)(OH)2; Epidote: Ca2(Al,Fe)3(SiO4)3(OH)

Amethyst

SiO2 (Silicon Dioxide)

Bauxite Ore

Hydrated aluminum oxides (e.g., Gibbsite Al(OH)3, Boehmite ̲̲̲̲AlOOH, Diaspore ̲̲̲̲AlOOH)