Mineral (Processed Alloy)

Gneiss

Gneiss (pronounced 'nice')

Shale or Mudstone (Based on appearance)

Shale (fine-grained, laminated fissile sedimentary rock) / Mudstone (fine-grained, non-fissile sedimentary rock)

Leopardskin Jasper

Jasper (a variety of microcrystalline Quartz)

Quartz (River-worn Pebble)

Quartz (SiO2)

Pink quartz bead strand (likely rose quartz or pink dyed quartz)

Quartz, silicon dioxide (SiO₂); probable rose quartz variety, possibly dyed or treated quartz/chalcedony

Honey-colored chalcedony (possibly yellow/orange agate or carnelian)

Chalcedony, a microcrystalline variety of quartz; SiO₂. The color may result from iron-oxide inclusions. Exact identification is uncertain from a photograph alone.

Amber

Fossilized Tree Resin (Amorphous Hydrocarbon)

Diamond (Rough)

Diamond (C)

Quartz

Quartz (SiO2, Silicon Dioxide)

Clear Quartz (beads in a bracelet)

Quartz (SiO2)

Chalcedony (Banded/Mottled Variety)

Chalcedony (a cryptocrystalline variety of Quartz, SiO2)

Amber

(C10H16O)n – an amorphous organic substance, primarily composed of polymerized isoprenoids.

Basalt

Basalt

Chert / Flint (a variety of Chert)

Chert (SiO2)

Ironstone Concretion (likely)

Goethite/Hematite/Limonite cemented sediment

Shale or Argillite

Shale (sedimentary) / Argillite (metamorphic)

Tiger's Eye

Tiger's Eye (a variety of Quartz, SiO₂)

Banded Gneiss (River Rock/Pebble)

Gneiss (specifically a banded variety, likely a orthogneiss or paragneiss depending on parent rock)

Opal

Hydrous silicon dioxide (SiO2·nH2O)

Marble

Metamorphosed Limestone/Dolomite

Sandstone (Pebble/Conglomerate fragment)

Sandstone (clastic sedimentary rock)

Quartz

Silicon dioxide (SiO₂)

Fuchsite Quartzite

Fuchsite-bearing Quartzite

Pumice (likely)

Pumice (extrusive igneous rock)

Banded Chert / Banded Jasper (likely a variety of Chert/Chalcedony)

Chert (microcrystalline quartz)

Dark-colored Igneous Rock (likely Basalt or Diabase)

Basalt (extrusive igneous) or Diabase (intrusive igneous)

Lapis Lazuli

Lapis Lazuli (a rock type, not a single mineral, composed primarily of lazurite, calcite, and pyrite)

Quartz (variety of colors)

SiO2 (Silicon Dioxide)

Serpentinite

Serpentinite (composed primarily of serpentine minerals like antigorite, chrysotile, and lizardite)

Red Jasper

Jasper (a variety of Chalcedony, SiO₂ with iron oxide inclusions)

Halite (Rock Salt)

Halite; NaCl (Sodium Chloride)

Citrine Geode (or Druzy Citrine)

Silicon Dioxide (SiO₂) - a variety of Quartz

River Rock

Sedimentary Rock (various compositions)

Tektite (likely Australite)

Tektite (no specific chemical formula as it's a natural glass of variable composition, mostly SiO2, Al2O3, FeO, MgO, CaO, K2O, Na2O, TiO2)

Amber (Black)

Amber (succinite, retinite, etc., specifically, heavily included/dark varieties)

Quartz

Quartz (SiO₂ - Silicon Dioxide)

Amethyst Geode/Cluster

Quartz (SiO2) - variety Amethyst

Quartzite

Quartzite

Petrified Wood

Silicified wood, primarily composed of Quartz (SiO2)

Sandstone (likely a river or beach pebble)

Sandstone (a clastic sedimentary rock)

Shale

Shale (fine-grained clastic sedimentary rock)

Mother of Pearl (Nacre)

Calcium Carbonate (primarily aragonite, with conchiolin)