Sedimentary And Metamorphic

Pyrite-bearing rock (iron pyrite)

Pyrite, FeS₂, likely disseminated or massive in a host rock

Polished malachite

Malachite, Cu₂CO₃(OH)₂

Red Jasper

Silicon Dioxide (SiO2) with Hematite impurities

Tumbled quartz-rich pebble

Microcrystalline quartz (SiO₂), possibly milky quartz or chalcedony

Jasper

Jasper (Silicon Dioxide, SiO2)

Jasper (Red Jasper)

Silicon Dioxide (SiO2) with Hematite inclusions

Green calcite (probable)

Calcite, calcium carbonate (CaCO₃)

Fossil shark tooth

Likely fossilized shark tooth, possibly Carcharhinus or Otodus species

Pearl

Pearl; primarily aragonite (CaCO₃) in nacre

Pyrite-bearing rock (likely pyrite-rich quartz or schist)

Pyrite, FeS₂, intergrown with quartz and/or mica-rich matrix

Red Jasper

SiO2 (Silicon Dioxide with Iron inclusions)

Desert rose

Gypsum (selenite) rosette, CaSO₄·2H₂O

Pearl-bearing oyster shell

Nacreous shell, primarily aragonite (CaCO₃), with natural pearls (calcium-carbonate nacre)

Feldspar-rich Quartzite

Metamorphic Quartz-Feldspar Aggregate (SiO2 + KAlSi3O8)

Red Jasper (Opaque Chalcedony)

Silicon Dioxide (SiO2) with Hematite inclusions

Jasper

Silicon dioxide (SiO2)

Yellow-green serpentine (likely)

Serpentine-group phyllosilicate, commonly lizardite or antigorite; approximate formula Mg₃Si₂O₅(OH)₄

Pearl

Nacre (aragonite, CaCO₃, in an organic conchiolin matrix)

Limonite Pseudomorph after Pyrite

Goethite/Limonite FeO(OH)·nH2O replacing Pyrite FeS2

Banded calcite (likely cave deposit or vein fragment)

Calcite, CaCO₃

Tumbled amethyst

Amethyst, purple variety of quartz (SiO₂)

Pearl necklace

Pearl—biogenic calcium carbonate, primarily aragonite (CaCO₃)

Likely anthracite coal fragments

Anthracite; predominantly carbon (C), with minor mineral ash

Banded Chert / Banded Jasper (likely a variety of Chert/Chalcedony)

Chert (microcrystalline quartz)

Sandstone or Quartzite

Arenite (if sedimentary) / Quartzite (if metamorphic)

Sandstone or Quartzite

Sandstone or Quartzite (SiO2 primarily)

Quartz (chalcedony variety) or Limestone with Quartz Veins

SiO2 (for Quartz/Chalcedony); CaCO3 (for Limestone)

Shale or Slate

Shale (Sedimentary) or Slate (Metamorphic)

Weathered quartz-rich rock, likely chert or quartzite

Microcrystalline quartz (SiO₂), possibly with iron-oxide staining

Pyrite (or Fool's Gold)

Pyrite (FeS₂)

Carnelian

Carnelian (a variety of Chalcedony, SiO ₂)

Tumbled golden-brown stone, likely sandstone or iron-stained quartzite

Indeterminate from image; probable quartz-rich sandstone (SiO₂) or quartzite

Quartzite / Sandstone / Chert Mix

Silicon Dioxide (SiO2)

Tumbled reddish-brown pebble, likely sandstone or iron-rich quartzite

Probable ferruginous sandstone (quartz-rich; SiO₂ with iron oxides), possibly quartzite

Sandstone, Quartzite, and River Pebbles

Silicon Dioxide (SiO2) based Sedimentary/Metamorphic structures

Weathered iron-rich stone, possibly chert or quartzite

Indeterminate; likely silica-rich rock with iron-oxide staining (SiO₂-dominant)

Jasper

Chalcedony (Microcrystalline Quartz) - SiO2

Tumbled reddish-brown stone, possibly jasper or iron-rich quartzite

Uncertain from image; likely microcrystalline quartz (SiO₂) with iron-oxide inclusions

Sandstone or Quartzite pebble

Sandstone (Quartz arenite) or Quartzite

Jasper or Red Quartzite

SiO2 (Silicon Dioxide with iron oxide impurities)

Banded Sandstone or Quartzite Pebble

SiO2 (dominant) with impurities

Quartz with Iron Stains

Quartz (SiO2) with iron oxide/hydroxide staining