Tektite (Natural Glass)

Green Calcite or Prasiolite (Green Quartz)

Calcium carbonate (CaCO3) or Silicon dioxide (SiO2)

Citrine (Raw)

Silicon Dioxide (SiO2) with iron impurities

Tumbled aqua glassy mineral specimen, likely chrysocolla or turquoise imitation

Uncertain from image; possible chrysocolla (hydrated copper aluminosilicate, variable composition) or dyed/man-made glass

Mahogany Obsidian

Volcanic Glass (predominantly SiO2 with Hematite/Magnetite inclusions)

Strawberry Quartz

Silicon Dioxide (SiO2) with Hematite or Goethite inclusions

Sandstone (likely Arkosic or Lithic Sandstone)

Clastic Sedimentary Rock (SiO2 with assorted minerals)

Sandstone

Arenite (primarily SiO2)

Sandstone (with Iron Oxide staining)

Arenite (primarily SiO2 with Fe2O3 staining)

Sandstone (with Iron Staining)

Clastic sedimentary rock (primarily Quartz with Hematite/Limonite oxides)

Sandstone

Arenite

Quartz-rich stone, possibly aventurine quartz or quartzite

Quartz (SiO₂), likely massive or microcrystalline; exact identification requires testing

Carnelian/chalcedony rough

Microcrystalline quartz (SiO₂), iron-oxide-colored chalcedony

Weathered quartz-rich rock, possibly milky quartz or quartzite

Quartz (SiO₂), potentially quartzite if recrystallized sandstone

Blue Slag Glass

Amorphous Silica (Byproduct of smelting)

Black spinel bead bracelet

Spinel (magnesium aluminate), MgAl₂O₄

Cullet Glass (Man-made Glass Slag)

Amorphous Silica (SiO2) with chemical additives

Rounded quartz-rich pebble

Quartz (SiO₂), possibly milky quartz or quartzite

Amethyst Beads

Quartz (Silicon Dioxide, SiO2 with iron impurities)

Quartzite with inclusions or a banded chert

Quartzite or Chert

Quartz (Gravel Pebble)

Silicon Dioxide (SiO2)

Slag Glass (Cullet)

Amorphous Silica (man-made), primarily SiO2 with trace metal oxides

Quartz cabochon turtle pendant

Quartz (SiO₂), likely a translucent variety with natural inclusions

Polished chalcedony (likely moss or dendritic agate)

Microcrystalline quartz, SiO₂; chalcedony with possible iron-oxide and/or manganese dendrites

Amethyst cluster

Quartz, silicon dioxide (SiO₂), purple variety colored mainly by iron-related defects

Tumbled pink quartz, possibly rose quartz

Quartz (SiO₂), likely rose quartz; exact identification requires testing

Yellow Quartzite Pebble

Quartzite (SiO2)

Flint / Chert

Microcrystalline quartz (SiO2)

Orange Quartzite (or Quartz River Pebble)

Silicon Dioxide (SiO2) - Quartzite

Blue gemstone, likely tumbled sapphire or blue spinel

Corundum (Al₂O₃) if sapphire; alternatively spinel (MgAl₂O₄)

Yellow Chalcedony (Tumbled/Cabochon)

Silicon dioxide (SiO2)

Citrine

Silicon Dioxide (SiO2)

Polished crescent-shaped stone pendant

Likely black jade, basalt, or other dark silicate stone; exact identification requires testing

Cubic Zirconia

Zirconium dioxide (ZrO2)

Diamond

Carbon (C), Native Element

Chert (Jasper/Carnelian variety)

Microcrystalline Quartz (SiO2)

Milky Quartz with Iron Inclusions

Silicon Dioxide (SiO2) with Hematite/Limonite

Quartz pebble (Agate / Chalcedony)

Silicon Dioxide (SiO2)

Epidote (Unakite component) / Green Quartzite

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

Quartz (Citrine or Iron-Stained)

Silicon Dioxide (SiO2)

Polished banded obsidian

Volcanic glass, predominantly SiO₂; likely banded or mahogany obsidian

Green Aventurine

Silicon Dioxide (SiO2) with Fuchsite inclusions

Green Aventurine

Silicon Dioxide (SiO2) with Fuchsite inclusions