Sedimentary (Processed Mineral Product)

Iron-rich slag or ironstone; appearance is not diagnostic

Likely iron-oxide-rich material (hematite, Fe₂O₃, and/or magnetite, Fe₃O₄); possibly smelting slag

Gold-bearing placer gravel (possible gold flakes)

Unconsolidated alluvial sediment containing quartz, lithic fragments, and possibly native gold (Au)

Iron-stained rock fragment (possibly limonite/goethite-rich)

Likely limonite, a mixture of hydrated iron oxides; may include goethite (α-FeO(OH))

Hematite

Iron(III) oxide (Fe2O3)

Turquenite (Dyed Howlite)

Dyed Ca2B5SiO9(OH)5 (Calcium Borosilicate Hydroxide)

Epidote

Epidote; Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)

Dyed Pink Agate (Crackled)

Silicon Dioxide (SiO2) - Chalcedony variety

Hematite

Hematite (Fe2O3)

Serpentine

Serpentinite (composed primarily of Mg3Si2O5(OH)4)

Hematite

Iron(III) oxide (Fe2O3)

Mixed Mineral Collection (with Titanium Aura Quartz)

Silicon Dioxide (SiO2) with metallic coatings and various silicates

Mica Schist with Garnet

Garnetiferous Mica Schist

Hematite

Iron (III) Oxide (Fe2O3)

Limonite and Goethite encrusted Chert/Ironstone

Hydrated Iron Oxide (FeO(OH)·nH2O) with cryptocrystalline Silica (SiO2)

Polished banded calcite (often sold as “onyx marble” or Mexican onyx)

Banded calcite; predominantly CaCO₃, usually microcrystalline to fibrous calcite

Mixed Quartz and River Pebbles (Stone Collection)

Mixed assortment containing mainly Silicon Dioxide (SiO2)

Pyrite-bearing rock, likely quartz vein

Pyrite (FeS₂) in quartz-rich host rock

Botryoidal Hematite (Iron Stone Conglomerate)

Hematite (Fe2O3) in sedimentary matrix

Banded Iron Formation (BIF)

Banded Iron Formation (Magnetite-Hematite-Chert)

Likely biotite-rich mica schist

Mica schist, chiefly biotite (K(Mg,Fe)₃AlSi₃O₁₀(OH,F)₂), with possible quartz and feldspar

Marble

Recrystallized Calcite (CaCO3)

Sandstone (Red Flagstone)

Clastic sedimentary rock (primarily Quartz - SiO2)

Likely silver-gray metallic ore fragment

Unidentified metallic mineral; possibly galena (PbS), but the image is insufficient for a confident identification

Dumortierite Quartz

Dumortierite in Quartz (Al6O3(BO3)(SiO4)3)

Turquoise-style beaded bracelet

Turquoise, hydrated copper–aluminum phosphate: CuAl₆(PO₄)₄(OH)₈·4H₂O; possibly dyed or composite beads

Red Hematite (Iron Ore)

Hematite (Fe2O3)

Slate

Slate (foliated metamorphic rock)

Beach Agate / Chalcedony Pebble

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Generic Pebble / Rock Fragment

Lithic fragment / Weathered rock pebble

Earthy iron-rich clay or weathered laterite

Hydrated iron oxides and clay minerals, commonly goethite/hematite with kaolinite or illite

Sandstone-based Concrete Fragment

Cementitious Composite with Sedimentary Aggregate

Quartz Pebble

Silicon Dioxide (SiO2)

Cobalt Blue Slag Glass

Amorphous Silicon Dioxide (anthropogenic) with Cobalt additives

Limonite

Hydrous Iron Oxide (often Goethite FeO(OH), Lepidocrocite γ-FeO(OH), and other amorphous iron oxyhydroxides)

Pale green translucent mineral fragment

Indeterminate; possibly fluorite, calcite, or glassy quartz

Quartzite

Quartzite (primarily SiO2)

Fossil shell fragment

Indeterminate molluscan bioclast, likely aragonite or calcite

Tumbled greenstone (likely serpentine-rich)

Greenstone; commonly metamorphosed mafic rock composed of actinolite/chlorite with epidote and albite

Tumbled gray chalcedony (agate-like quartz)

Chalcedony, microcrystalline SiO₂

Mixed gemstone bead strand, likely including agate, quartz, turquoise, and sandstone beads

Varied silicate and copper-mineral materials; exact bead identities cannot be confirmed visually

Dyed Quartz Crystals

Silicon Dioxide (SiO2) with artificial pigment

Slate

Foliated Metamorphic Slate