Synthetic Material (Not A Rock Or Mineral)

Sandstone (Ferruginous)

Arenite (variable SiO2 with Fe2O3 staining)

Sandstone (Quartzose Sandstone)

Clastic sedimentary rock (primarily SiO2)

Tumbled jasper, likely red/brown jasper

Microcrystalline quartz (chalcedony), SiO₂, colored by iron oxides

Sandstone (Ferruginous)

Arenite with Iron Oxide cement

Greenish Metamorphic Rock (likely containing epidote or chlorite)

Metamorphic rock, possibly epidosite or greenstone

Sapphire

Corundum (Al₂O₃) with trace elements causing color variations.

Olivine (Peridotite)

(Mg,Fe)2SiO4 (Magnesium Iron Silicate)

Sandstone (Ferruginous)

Sandstone (primarily SiO2 with iron oxide cement Fe2O3)

Quartz (Milky/Yellowish variety)

Silicon Dioxide (SiO2)

Mica-rich granite (likely biotite granite)

Biotite granite; mainly quartz (SiO₂), alkali/feldspar, and biotite mica

Granodiorite

Granodiorite

Sandstone (Ferruginous)

Arenite (composed primarily of SiO2 with Fe2O3 cement)

Tumbled pegmatitic granite

Granite, chiefly quartz–feldspar–mica; likely altered pegmatite

Sandstone (Ferruginous)

Clastic sedimentary rock (SiO2 with Fe2O3)

Greenish Feldspathic Rock / Epidote Granite (Unakite-type or Epidote-bearing rock)

Epidotized Metamorphic/Igneous Rock

Coal (Anthracite / Bituminous)

Organic Sedimentary Rock (Carbon-based)

Sandstone (likely Fossiliferous Sandstone)

Clastic sedimentary rock (primarily SiO2)

Serpentine (Serpentinite)

Serpentinite (complex silicate group including lizardite, chrysotile, and antigorite)

Granite (Polished Slab)

Granite (Plutonic Igneous Rock)

Small rounded pebble, likely quartz-rich river stone

Indeterminate; likely quartz/chert-bearing lithic clast

Limonite (Yellow Ochre)

FeO(OH)·nH2O (Hydrous iron(III) oxide-hydroxide mixture)

Fossil Shark Tooth

Chondrichthyes tooth fossil

Brecciated Chert

Sedimentary Chert (SiO2) with Calc-Silicate mineralization

Weathered granitic rock fragment

Likely granite or granodiorite, composed mainly of quartz, feldspar, and mica

Fossilized oyster or bivalve shell

Fossil Gryphaeidae or Ostreoidea; calcitic shell, CaCO₃

Sandstone (Ferruginous Concretion)

Arenite (with iron oxide cement)

Sandstone (Quartzose)

Arenite (primarily SiO2)

Sandstone (with Iron Staining)

Clastic Sedimentary Rock (primarily SiO2 with FeO(OH) impurities)

Limestone

Calcium Carbonate (CaCO3)

Sunstone

Oligoclase or Andesine (Plagioclase Feldspar) - (Ca, Na)((Al, Si)2Si2O8)

Sandstone

Arenite (composed primarily of SiO2)

Tumbled tree agate (dendritic agate)

Cryptocrystalline quartz, SiO₂, with manganese/iron-oxide dendrites

Goldstone (aventurine glass)

Man-made copper-bearing glass; not a natural mineral (commonly sold as blue/brown goldstone)

Tree Agate (or Moss Agate)

Dendritic Agate (Silicon Dioxide - SiO2)

Sandstone Pebble (River Rock)

Sandstone (Quartz-rich sedimentary rock with iron oxide staining)

Sandstone

Arenite (primarily SiO2)

Tumbled jasper (likely ocean or orbicular jasper)

Microcrystalline quartz (chalcedony), SiO₂, with iron oxides and dark accessory minerals

Red jasper (iron-rich chalcedony), possibly brecciated

Jasper: microcrystalline quartz, SiO₂, colored mainly by iron oxides/hydroxides

Green Slag Glass

Cullet (Amorphous Silicon Dioxide with impurities)

Sandstone

Arenite (composed primarily of SiO2)

Sandstone Pebble

Arenite (SiO2 primarily)

Sandstone (likely Graywacke or Arkose)

Clastic Sedimentary Rock (primarily SiO2 with various lithic fragments)