Basalt

Ruby

Corundum (Al₂O₃) with Chromium (Cr)

Banded Agate (likely Carnelian Agate or Sardonyx)

Agate is a common name for a microcrystalline variety of Quartz (SiO₂), specifically a form of Chalcedony.

Hypersthene

Hypersthene ((Mg,Fe)SiO₃)

Amethyst

SiO2 (Silicon Dioxide) - a variety of Quartz

Black Chert

Chert (microcrystalline quartz)

Chalcedony Geode

Chalcedony (SiO2) within a geode structure

Pumice

Pumicite (fine-grained pumice), Scoria (similar origin but denser and darker, usually basaltic)

Peridot and Citrine Gemstones (in a ring setting)

Peridot (Olivine: (Mg,Fe)2SiO4), Citrine (Quartz: SiO2)

Schist

Schist (various mineral compositions)

Schist

Schist (various mineral compositions)

Agate (specifically, likely a geode slice or nodule)

Agate (a variety of Chalcedony, with chemical formula SiO2)

Blue Chalcedony

Chalcedony (a cryptocrystalline variety of Quartz - SiO₂)

Banded River Pebble (Gneiss or Quartz-Veined Basalt)

Polished River Siltstone or Quartzite Gneiss

Baroque Pearl (and potentially a small Sapphire/Blue Topaz)

Pearl: Calcium Carbonate (aragonite or calcite) with conchiolin. Sapphire: Aluminum Oxide (Al2O3). Blue Topaz: Al2SiO4(F,OH)2.

Serpentine

Serpentine group minerals (e.g., Antigorite, Chrysotile, Lizardite). Chemical formula: (Mg, Fe)₃Si₂O₅(OH)₄

Gneiss (likely)

Gneiss

Chalcedony (Banded/Mottled Variety)

Chalcedony (a cryptocrystalline variety of Quartz, SiO2)

Agate (or Banded Agate)

Agate (a variety of Chalcedony, which is a cryptocrystalline form of Quartz); Chemical Formula: SiO₂ (Silicon Dioxide)

Carnelian

Chalcedony (cryptocrystalline quartz), SiO2

Quartz Geode (likely within Limestone or Dolomite matrix)

Quartz (SiO₂)

Sapphire

Corundum (Al₂O₃) with trace elements causing color variations.

Quartz (Druzy) in host rock

SiO₂ (Silicon Dioxide) as Quartz, with unspecified host rock components (likely silicates and iron oxides)

Epidote (or Epidote-rich rock)

Epidote. Mineral formula: Ca2(Al,Fe)3(SiO4)3(OH).

Amethyst Geode/Cluster

Quartz (SiO2) - variety Amethyst

Sapphire (likely blue synthetic sapphire or blue glass in a ring)

Corundum (Al₂O₃), specifically the blue variety due to trace amounts of iron and titanium impurities. If synthetic, it would still be Al₂O₃.

Note: The image provided is a fabric sock, not a geological specimen.

Polyester-Cotton Blend with Elastane

Fossilized Stingray Mouth Plate

Myliobatidae dental battery

River Cobble (likely Sandstone or Siltstone type)

Sandstone or Siltstone (common rock types that form river cobbles)