Tektite (Natural Glass)

Uncertain blue-white mineral fragment

Possibly calcite or quartz; identification is limited because the specimen is tiny and partly translucent

Smoky Quartz

Silicon Dioxide (SiO2) with aluminum impurities

Obsidian

Obsidian (Volcanic Glass, SiO2)

Blue Goldstone

Synthetic Aventurescent Glass (Cobalt-doped soda-lime glass)

Tumbled blue chalcedony or dyed quartz

Microcrystalline quartz, SiO₂ (likely dyed chalcedony)

Polished black obsidian

Volcanic glass; primarily rhyolitic SiO₂, with minor iron, magnesium, and other trace elements

Green Aventurine

Silicon Dioxide (Quartz) with Fuchsite inclusions (SiO2 + K(Al,Cr)2(AlSi3O10)(OH)2)

Green Aventurine

Aventurine Quartz (SiO2 + Fuchsite inclusions)

Green Aventurine

Quartz with Fuchsite inclusions (SiO2)

Green Aventurine

Silicon Dioxide with Fuchsite inclusions (SiO2 + K(Al,Cr)2AlSi3O10(OH)2)

Blue chalcedony (likely dyed or polished)

Chalcedony, microcrystalline quartz (SiO₂)

Green Aventurine

Silicon Dioxide (SiO2) with Chromium-bearing Fuchsite

Green Aventurine

Silicon Dioxide (SiO2) with Fuchsite inclusions

Green Aventurine

SiO2 (Silicon Dioxide with inclusions of Fuchsite mica)

Green Aventurine

Silicon Dioxide (SiO2) with Fuchsite inclusions

Mahogany Obsidian

Volcanic Glass with Hematite inclusions (SiO2 + Fe2O3)

Green Aventurine

Silicon Dioxide (SiO2) with inclusions of Fuchsite (K(Al,Cr)2(AlSi3O10)(OH)2)

Aventurine

Aventurine (Silicon Dioxide with Fuchsite inclusions) - SiO2

Green Aventurine

Aventurine Quartz (SiO2 with Fuchsite inclusions)

Green Aventurine

Silicon Dioxide (SiO2) with inclusions of Fuchsite mica

Green Aventurine

Aventurine Quartz (SiO2 with inclusions of Fuchsite)

Green Aventurine

Silicon dioxide (SiO2) with Fuchsite inclusions

Green Aventurine

Aventurine Quartz (SiO2 + Fuchsite mica)

Green Aventurine

Aventurine Quartz (SiO2 with Fuchsite inclusions)

Green Aventurine

Silicon Dioxide (SiO2) with Fuchsite inclusions

Green Aventurine

Aventurine Quartz (SiO2 with Fuchsite inclusions)

Citrine

Silicon Dioxide (SiO2) - Macrocrystalline Quartz variety

Polished white chalcedony or quartz pendant

Microcrystalline quartz (chalcedony), SiO₂; exact identification is uncertain from the image

Silicon Carbide (Carborundum)

Silicon Carbide (SiC) / Moissanite (natural)

Tumbled quartz-rich pebble

Quartz (SiO₂), likely with iron-oxide staining and minor inclusions

Pumice

Pumice (Amorphous volcanic glass)

Citrine (or Yellow Chalcedony / Quartz)

Silicon Dioxide (SiO2)

Chert (Banded)

Microcrystalline Quartz (SiO2)

Zirconia (Ceramic) & Ion-X Glass

Zirconium Dioxide (ZrO2) and Ion-strengthened Aluminosilicate Glass

Likely gold-colored metal ring with a possible gemstone

Uncertain; possibly gold alloy (Au) with a small quartz or glass-like setting

Tumbled milky chalcedony (likely common opalite-like quartz)

Chalcedony, microcrystalline SiO₂; possibly pale common opal, hydrated SiO₂·nH₂O

Red Quartzite Pebble

Quartzite (SiO2)

Smoky Quartz

Silicon Dioxide (SiO₂)

Dyed agate (likely dyed chalcedony)

Microcrystalline quartz, SiO₂ (chalcedony/agate)

Aventurine

Silicon Dioxide (SiO2) with inclusions of Fuchsite

Likely clear quartz pebble or glassy quartz fragment

Quartz (silicon dioxide, SiO₂)

Smoky Quartz with Iron Inclusions

Silicon Dioxide (SiO2)