Igneous And Sedimentary Mixture

Carnelian / Chalcedony

Cryptocrystalline Quartz (SiO2)

Marble

Marble (metamorphosed limestone or dolostone), primarily composed of calcite (CaCO3) or dolomite (CaMg(CO3)2)

Epidote

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

Polished magnetite-rich ironstone (possible magnetite pebble)

Magnetite, Fe₃O₄; possibly magnetite-bearing basalt or ironstone

Chert (varietal: Jasper or Flint likely, but definitive identification is difficult from image)

SiO₂ (silicon dioxide)

River Stone (composed of Siltstone/Basalt mixture)

Siltstone or microcrystalline Basalt pebble

Chalcedony (Agate/Carnelian precursor)

Chalcedony (Silicon Dioxide, SiO2)

Pyrite in Quartz Matrix

Iron Disulfide (FeS2) in Silicon Dioxide (SiO2)

Limonite (Iron Ore)

Limonite (an FeO(OH)·nH2O mineraloid, not a true mineral due to variable composition)

Bumblebee Jasper (technically Bumblebee Stone)

Calcite, Aragonite, and Realgar/Orpiment mixture (SiO2 + CaCO3 + As2S3/As2S2)

Chert (potentially Jasper/Common Opal mixture)

Microcrystalline Quartz (SiO2)

Amethyst

Amethyst (Silicon Dioxide - SiO2 with iron impurities)

Carnelian (Tumbled)

Carnelian (Chalcedony / Silicon Dioxide, SiO2)

Pyrite

Iron Sulfide (FeS2)

Mixed river-worn rock and mineral collection

Mostly quartz/quartzite, feldspar-bearing granitoid, chert, and mafic volcanic rocks; exact species vary by pebble

Weathered iron-rich rock, possibly limonite/goethite-bearing breccia

Hydrated iron oxides/hydroxides, mainly limonite (mixture) and goethite, FeO(OH)·nH₂O

Moonstone

Adularia (orthoclase) or Albite (plagioclase), a feldspar mineral (KAlSi3O8 or NaAlSi3O8 respectively, often a mixture)

Quartz (Milky/Smoky variety on matrix)

Silicon Dioxide (SiO2)

Tumbled milky quartz

Quartz (silicon dioxide, SiO₂)

Milky quartz crystal cluster

Quartz (silicon dioxide, SiO₂)

Blue Apatite

Fluorapatite (Ca5(PO4)3F)

Likely milky quartz

Quartz (silicon dioxide, SiO₂)

Magnetite / Ironstone

Magnetite (Fe3O4)

Chert (specifically Yellow/Common Opal or Jasper mixture)

Silicon Dioxide (SiO2)

Milky quartz

Quartz (silicon dioxide, SiO₂)

Weathered iron-rich rock (probable laterite or limonite-bearing stone)

Goethite–limonite mixture, commonly written FeO(OH)·nH₂O, with possible quartz and clay minerals

Bauxite (Laterite Clay)

Bauxite (mixture of Hydrous Aluminum Oxides: Gibbsite Al(OH)3, Boehmite and Diaspore AlO(OH))

Apatite

Fluorapatite (Ca5(PO4)3F)

Shale

Shale (fine-grained clastic sedimentary rock)

Small quartz-rich mineral fragment

Quartz (SiO₂), possibly milky or chalcedonic quartz

Quartz

Silicon dioxide (SiO2)

Dalmatian Jasper

Aplite with Arfvedsonite inclusions

Weathered iron-rich rock, possibly laterite or limonite-bearing sandstone

Laterite/limonite mixture; primarily hydrated iron oxides such as goethite (FeO(OH)) and iron-rich clay minerals

Weathered iron-rich concretion or limonite-bearing rock

Limonite/goethite-rich concretion; limonite is an iron-oxide/hydroxide mixture, commonly dominated by goethite (FeO(OH))

Magnetite (Lodestone variety)

Magnetite (Fe3O4)

Magnetite

Iron(II,III) oxide (Fe3O4)

Pet Rock (Man-made Quartzite or Granite Cobble)

Silicon dioxide (SiO2) mixture; commonly composed of Quartz, Feldspar, and Mica

Quartz pebble

Silicon dioxide (SiO2)

Clear Quartz

SiO2 (Silicon Dioxide)

Mica

Mica group (often Muscovite or Biotite)

Clear Quartz

Silicon Dioxide (SiO2)

Milky quartz

Quartz, silicon dioxide (SiO₂)