Mineraloid (Man Made Glass)

Obsidian

Volcanic Glass (predominantly SiO2, approximately 70% or more)

Obsidian (black volcanic glass)

Obsidian; predominantly rhyolitic volcanic glass, mainly SiO₂ with minor feldspar, quartz, and iron oxides

Black Opal (Triplet)

Hydrated Silica (SiO2·nH2O)

Limonite (Iron Ore)

Limonite (Hydrated Iron Oxide, FeO(OH)·nH2O)

Mahogany Obsidian

Volcanic glass (SiO2 + Fe2O3)

Mahogany Obsidian

Obsidian (volcanic glass with hematite/magnetite inclusions)

Likely clear quartz crystal (possibly cut/polished quartz or glass imitation)

Quartz, silicon dioxide (SiO₂)

Colorless faceted gemstone, likely glass or quartz

Uncertain; possibly quartz (SiO₂), but the strong uniform brilliance and apparent molded/faceted form may indicate leaded glass or cubic zirconia

Limonite (Iron Ore)

Hydrated Iron(III) Oxide-Hydroxide (FeO(OH)·nH2O)

Black Obsidian

Volcanic glass (Amorphous silicates)

Limonite (Ironstone)

Limonite (mixture of hydrated iron oxides, primarily Goethite α-FeO(OH))

White Opal

Hydrated Silica (SiO2·nH2O)

Abalone Shell (Nacre)

Aragonite (CaCO3) - Biogenic Mineral

Obsidian

Volcanic Glass (comprised primarily of SiO2)

Pumice

Pumice (Vesicular volcanic glass)

Obsidian

Volcanic Glass (70% or more SiO2)

Green Aventurine

Silicon Dioxide (SiO2) with inclusions of Fuchsite

Aventurine

Silicon Dioxide (SiO2) with inclusions of Fuchsite

Diamond (or Diamond Simulant)

Carbon (C) or Cubic Zirconia (ZrO2)

Blue Goldstone

Aventurine Glass (Silicon Dioxide infused with Cobalt/Copper)

Chert (Flint)

Silicon dioxide (SiO2)

Black Obsidian

Obsidian (Volcanic Glass), primarily SiO2 (Silicon Dioxide)

Sea Glass (Cobalt Blue)

Amorphous Silica (Glass with Cobalt additives)

Small yellow-orange mineral fragment, likely amber or iron-stained quartz

Possibly amber (fossilized resin; organic mineraloid) or quartz (SiO₂)

Obsidian

Volcanic glass (silica-rich rhyolitic melt; primarily SiO₂)

Pumice

Pumice (Vitreous volcanic rock)

Black Obsidian

Volcanic Glass (predominantly SiO2, Silicon Dioxide)

Fired Clay Brick (Anthropic Rock substitute)

Anthropogenic polycrystalline ceramic (predominantly Mullite and Quartz: Al6Si2O13 + SiO2)

Faceted colorless gemstone, likely quartz or glass imitation

Most likely quartz (SiO₂), though the strong glare and visible facet pattern could indicate cubic zirconia or lead glass

Pearl

Calcium Carbonate (Aragonite) with Conchiolin; formula: CaCO3

Mahogany Obsidian

Volcanic Glass (SiO2 with Fe/Mg oxides)

Amber in Matrix

Succinite (Carbon-based organic polymer)

Amber (polished piece)

Fossilized tree resin; amber is an organic mineraloid, not a true mineral

Yellow amber beads

Amber (fossilized tree resin; organic mineraloid, not a true mineral)

Obsidian

Volcanic Glass (Primary composition: SiO2 - Silicon Dioxide)

Chert (specifically Tan/Gray Chert)

Microcrystalline quartz (SiO2)

Shungite

Carbon-rich mineraloid (Amorphous carbon)

Goldstone and pink quartz bead strands

Goldstone is aventurescent copper-bearing glass; pink beads are likely rose quartz (SiO₂), though dyed or glass imitations are possible

Native Silver

Silver (elemental Ag)

Blue Sea Glass

Amorphous Silica (Anthropogenic glass)

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)

Nickel coin (U.S. currency)

Cupronickel (75% Copper, 25% Nickel alloy)