Sedimentary (Processed Mineral Product)

Kyanite

Al2SiO5

Quartz with Limonite Staining

Silicon Dioxide (SiO2) with Hydrated Iron Oxide (FeO(OH)·nH2O)

Botryoidal hematite (ironstone)

Hematite, α-Fe₂O₃, likely with goethite and iron-rich matrix

Epidote with quartz/feldspar

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

Small tumbled quartz-like pebble

Likely quartz (SiO₂), possibly iron-stained chalcedony or feldspar

Gossan (Iron Hat)

Gossan (secondary iron oxide cap)

Red Shale

Lutite (primarily composed of Hydrous Aluminum Silicates with Hematite staining)

Quartz Pebble

Silicon Dioxide (SiO2)

Hematite

Hematite (Fe2O3)

Granite Gneiss

Gneiss (High-grade Metamorphic Rock)

Opalite

Synthetic Glass / Man-made Opal Simulant

Iron-rich breccia (likely limonite/goethite-stained rock)

Ferruginous breccia; iron oxides/hydroxides such as goethite (FeO(OH)) and limonite, with unidentified rock fragments

Likely scoria (vesicular basalt)

Scoria, typically basaltic; composed mainly of plagioclase, pyroxene, and sometimes olivine

Quartz Geode or Druzy Quartz in Host Rock

Silicon Dioxide (SiO2)

Epidote

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

Sea Glass

Man-made silicate glass weathering product

Pumice

Pumice (extrusive volcanic rock)

Red jasper (tumbled)

Jasper, microcrystalline quartz/chalcedony (SiO₂) colored mainly by iron oxides

Dyed, polished stone beads (likely assorted agate or jasper)

Microcrystalline quartz, SiO₂ (chalcedony; exact stones cannot be determined from the image)

Bentonite Clay

Montmorillonite ((Na,Ca)0.33(Al,Mg)2Si4O10(OH)2·nH2O)

Blue Kyanite

Kyanite (Al2SiO5)

Rhodonite

Rhodonite (Manganese Iron Magnesium Calcium Silicate)

Heat-Treated Citrine (Amethyst-based)

Quartz (Silicon Dioxide) - SiO2

Iron-oxide-stained rock, possibly limonite-rich ore

Likely limonite/goethite-rich material; exact identification requires testing

Sandstone / Weathered Chert

Silicon Dioxide (SiO2) / Quartz-rich Clastic Rock

Limonite / Goethite Ironstone Concretion

FeO(OH)·nH2O (Hydrated Iron Oxide)

Likely serpentinite (serpentine-rich rock)

Serpentinite, composed mainly of serpentine-group minerals (lizardite, antigorite, or chrysotile); identification from the photo is tentative.

Chalcedony (Yellow Agate)

Cryptocrystalline Quartz (SiO2)

Hematite

Hematite (Fe2O3)

Epidote with Quartz

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

Polished agate (likely moss or plume agate)

Microcrystalline quartz (SiO₂), chalcedony variety; exact variety is uncertain from the photo

Tumbled green-yellow chalcedony (likely prehnite or serpentine)

Cryptocrystalline quartz (chalcedony), SiO₂; identification is uncertain from the photograph

Concrete aggregate surface

Human-made cementitious composite; primarily calcium-silicate-hydrate cement with mixed silicate aggregate

Clear quartz (rough quartz crystal)

Quartz, silicon dioxide (SiO₂)

Goethite / Limonite Gossan

Goethite, FeO(OH)

Tumbled jasper

Microcrystalline quartz (chalcedony), SiO₂; likely iron-stained jasper

Goethite

Goethite (FeO(OH))

Crushed Granite and Quartz Gravel

Composite Igneous and Silicate Rock Aggregate

Biotite Granite

Phaneritic Felsic Igneous Rock

Dead Sea Salt Crust

Halite (NaCl)

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

Iron oxides/hydroxides, chiefly limonite/goethite (FeO(OH)·nH₂O), with a probable silicate or clay matrix

Pyrite (likely)

Iron disulfide, FeS₂; commonly called fool’s gold