Sedimentary (Processed Mineral Product)

Weathered iron-rich limestone or altered volcanic rock

Probable limonite/goethite-bearing calcite rock; exact identification requires testing

Rounded quartz-rich pebble

Quartz-bearing lithic clast; exact rock type indeterminate from image

Quartz with Limonite Staining

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

Concrete aggregate surface

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

Yellow Jasper

SiO2 (Silicon Dioxide)

Epidote

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

Obsidian (likely black volcanic glass)

Obsidian; primarily amorphous volcanic silica glass, approximately SiO₂-rich rhyolitic composition

Concrete-like limestone or cemented carbonate rock

Likely limestone (calcium carbonate, CaCO₃); exact identification is uncertain from the image

Yellow Jasper

Silicon Dioxide (SiO2) with Iron Oxide inclusions

Faceted blue gemstone ring, likely synthetic spinel or glass; identity uncertain

Possibly synthetic blue spinel (MgAl₂O₄) or laboratory sapphire (Al₂O₃); the clear side stones may be cubic zirconia or glass

Blue Kyanite in Quartz

Kyanite (Al2SiO5)

Blue Onyx (Dyed Agate/Chalky Chalcedony)

Silicon Dioxide (SiO2) with artificial pigment

Dyed Agate

Silicon Dioxide (SiO2) with artificial pigment

Limonite / Goethite Ironstone Concretion

FeO(OH)·nH2O (Hydrated Iron Oxide)

Opalite

Synthetic glass / Opalized glass

Rhodonite

Rhodonite (Manganese Iron Magnesium Calcium Silicate)

Epidote with Quartz

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

Limestone

Sedimentary Calcium Carbonate (CaCO3)

Kambaba Jasper

Stromatolite Jasper (Microcrystalline Quartz with Fossilized Cyanobacteria)

Quartz-rich rock fragment (tentative)

Quartz, silicon dioxide (SiO₂), possibly in a weathered host rock

Tumbled pink feldspar (likely moonstone or orthoclase)

Potassium feldspar, chiefly orthoclase (KAlSi₃O₈); possibly adularescent moonstone

Goethite / Limonite Gossan

Goethite, FeO(OH)

Green aventurine bead bracelet

Quartz (SiO₂), commonly green quartzite/aventurine colored by fuchsite mica or other inclusions

Goethite

Goethite (FeO(OH))

Heat-Treated Amethyst (Commercial Citrine)

Silicon Dioxide (SiO2) - Macro-crystalline Quartz

Tumbled iron-rich concretion or ironstone pebble

Goethite–hematite-rich ironstone; commonly limonite (FeO(OH)·nH₂O) with hematite (Fe₂O₃)

Weathered quartz-rich rock, possibly granite or quartzite

Indeterminate; likely quartz–feldspar aggregate, potentially granitic, or recrystallized quartzite

Tiger’s eye beads

Tiger’s eye (quartz variety), SiO₂, with pseudomorphic fibrous crocidolite/goethite inclusions

Iron-rich concretion or weathered ironstone pebble

Goethite/limonite-bearing ironstone; commonly an iron-oxide concretion (FeO(OH)·nH₂O, variable)

Botryoidal Hematite (Kidney Ore)

Iron(III) oxide (Fe2O3)

Decorative polished stone tile, likely white marble or limestone

Calcite-rich marble (CaCO₃), possibly veined limestone; exact identification requires testing

Prehnite

Prehnite (Ca2Al(AlSi3O10)(OH)2)

Black Kyanite

Kyanite (Al2SiO5) with carbonaceous inclusions

Baltic Amber (Butterscotch or Egg Yolk Variety)

Succinite (C10H16O)

Pumice

Pumice (Volcanic glass / Felsic igneous rock)

Asphalt

Asphalt concrete (engineered material, not a naturally occurring rock/mineral in this form)

Banded brown jasper (likely picture jasper)

Silicified microcrystalline quartz/chalcedony (SiO₂), commonly iron-oxide stained

Blue calcite geode

Calcite (CaCO₃), commonly a druse-lined geode

Green glass sphere/marble

Soda-lime glass (primarily SiO2, Na2O, CaO)

Tumbled Tiger’s Eye

Quartz variety, fibrous SiO₂ with crocidolite pseudomorphs

Slate

Slate (Foliated Metamorphic Rock)

Tumbled yellow-green chalcedony or serpentine

Microcrystalline quartz (SiO₂), possibly chrysoprase; alternative: serpentine-group mineral