Igneous And Sedimentary Mixture

Limonite (Ironstone) Concretion

FeO(OH)·nH2O (Hydrous ferric oxide)

Granodiorite

Granodiorite (containing Plagioclase, Quartz, and K-feldspar)

Tumbled magnetite (likely)

Magnetite, Fe₃O₄; possibly magnetite-rich ironstone

Weathered ironstone concretion (probable limonite/goethite nodule)

Limonite-goethite-rich iron-oxide concretion; chiefly FeO(OH)·nH₂O

Chalcedony

Silicon dioxide (SiO2) - Microcrystalline quartz

Concrete

Anthropogenic Sedimentary Conglomerate (Cement mixture: typically Ca2SiO4, Ca3SiO5, Ca3Al2O6)

Yellow Chalcedony / Yellow Agate

Silicon Dioxide (SiO2)

River Stone (Quartzite/Chert mixture)

Microcrystalline Quartz (SiO2)

Agate

Chalcedony (SiO2)

Agate

Silicon Dioxide (Chalcedony), SiO2

Agate

Silicon dioxide (chalcedony variety), SiO2

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

Limonite/goethite-rich ferruginous sandstone; composition uncertain from the photograph

Zebra Jasper (Zebra Stone)

Silicon Dioxide (SiO2) with iron oxide and manganese inclusions

Mica-rich metamorphic rock, likely schist

Muscovite–biotite schist, possibly with quartz and feldspar

Grey Chalcedony (Agate)

Silicon Dioxide (SiO2)

Red garnet (likely almandine or pyrope), polished/tumbled

Garnet-group silicate; commonly almandine Fe₃Al₂(SiO₄)₃ or pyrope Mg₃Al₂(SiO₄)₃

Chert (and Chalcedony/Agate mixture)

Microcrystalline Quartz (SiO2)

Polished Tumbled Fluorite (or Dark Amethyst)

CaF2 (Calcium Fluoride) / SiO2 (Silicon Dioxide)

Tumbled quartz (likely milky or rose quartz)

Quartz, silicon dioxide (SiO₂)

Epidote

Epidote (Ca2(Al,Fe)3(SiO4)3(OH))

Uncertain blue-white mineral fragment

Possibly calcite or quartz; identification is limited because the specimen is tiny and partly translucent

Yellow iron-oxide-rich mineral/rock fragment

Likely limonite/goethite (hydrated iron oxides; commonly approximated as FeO(OH)·nH₂O)

Weathered iron-rich rock, possibly limonite-bearing sandstone

Limonite/goethite-bearing sandstone or ferruginous conglomeratic rock

Iron-rich weathered rock fragment

Indeterminate; likely limonite/goethite-bearing sandstone or lateritic ironstone

Carnelian (Carnelian Agate)

Carnelian (Silicon Dioxide - SiO2)

Carnelian Agate

Chalcedony (SiO2) with iron oxide inclusions

Dyed Agate

Chalcedony (SiO2)

Clear quartz crystal

Quartz (silicon dioxide, SiO₂)

Yellow quartz fragment (likely citrine or iron-stained quartz)

Quartz, silicon dioxide (SiO₂), trigonal crystal system

Milky quartz fragment

Quartz (silicon dioxide, SiO₂)

Multi-gemstone Quartz and Fluorite Bracelet

Silicon Dioxide (SiO2) and Calcium Fluoride (CaF2)

Epidote

Epidote (Ca2(Al2,Fe3+)3(SiO4)3(OH))

Quartz (Druzy)

Silicon Dioxide (SiO2)

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

Goethite–hematite/limonite mixture; exact identification requires testing

Silty Sand / Loam

Unconsolidated Clastic Sediment (Silicon Dioxide / Alumino-silicates mixture)

Septarian Nodule (Dragon Stone)

Septarian concretion (primarily Calcite, Aragonite, and Limestone/Claystone mixture)

Bauxite

AlOx(OH)3-2x (mixture of Gibbsite, Boehmite, and Diaspore)

Bauxite

Bauxite (Mixture of Al(OH)3, AlO(OH), and Fe2O3)

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

Limonite/goethite mixture (hydrated iron oxides), composition uncertain from image

Pyrite in Matrix

Iron Sulfide (FeS2)

Bornite (Peacock Ore) / Acid-treated Chalcopyrite

Bornite (Cu5FeS4) or Chalcopyrite (CuFeS2)

Likely lateritic ironstone (limonite/goethite-rich)

Goethite, α-FeO(OH), with possible limonite and clay impurities