Mineral (Specifically A Mineraloid)

Satin Spar (Satin Spar Selenite)

Gypsum (CaSO4·2H2O)

Yellow Ocher (Limonite)

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

Precious Coral (Red Coral)

Corallium rubrum (Calcium Carbonate, CaCO3)

Precious Opal

Hydrated Silica (SiO2·nH2O)

Obsidian

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

Opal

Hydrated silica (SiO2·nH2O)

Amber (Copal)

Fossilized Tree Resin

Opal

Hydrated amorphous silica (SiO2·nH2O)

Obsidian (volcanic glass), likely black obsidian

Rhyolitic volcanic glass; predominantly amorphous SiO₂

Obsidian (likely black obsidian)

Volcanic glass, predominantly rhyolitic to dacitic silica-rich melt; approximate composition ~70–75% SiO₂

Black obsidian

Volcanic glass, primarily rhyolitic silica glass (SiO₂-rich, noncrystalline)

Tumbled black stone, likely obsidian

Obsidian — volcanic glass, chiefly silica-rich rhyolitic composition

Tumbled black obsidian (likely)

Volcanic glass; chiefly silica-rich rhyolitic glass (SiO₂)

Tumbled black stone, likely black obsidian

Obsidian — natural volcanic glass, primarily SiO₂

Obsidian

Volcanic Glass (SiO2)

Obsidian

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

Larimar

NaCa2Si3O8(OH)

Kidney Stone

Nephrolithiasis (Calcium Oxalate, Hydroxyapatite, or Uric Acid)

Amber

Succinates

Amber

Succinite (with a generalized formula of C10H16O)

Opal

Hydrated Amorphous Silica (SiO2·nH2O)

Black Obsidian

Obsidian (Volcanic Glass)

Snowflake Obsidian

Volcanic Glass with Spherulite Inclusions (70–75% SiO2)

Mahogany Obsidian

Volcanic glass (SiO2 with Hematite or Magnetite inclusions)

Shungite

Carbon-rich mineraloid (Amorphous carbon)

Obsidian

Volcanic Glass (Amorphous Silica)

Amber

Succinite (Fossilized Tree Resin)

Amber (Raw)

Succinite (Fossilized Resin)

Moldavite

Silica glass with small amounts of aluminum, iron, and other elements

Amber

Succinates (Fossilized Tree Resin)

Boulder Opal

Hydrated Silica (SiO2·nH2O)

Limonite with Quartz (Gossan)

Hydrated iron(III) oxide-hydroxide mixture (FeO(OH)·nH2O) with Silicon Dioxide (SiO2)

Amber

Succinite (approximate formula C10H16O)

Amber

Succinite (C10H16O)

Pearl

Calcium Carbonate (Aragonite) with Conchiolin; formula: CaCO3

Pearls

Aragonite (calcium carbonate) and Conchiolin

Crazy Lace Agate

Chalcedony (Silicon Dioxide, SiO2)

Stilbite

Stilbite (Hydrated calcium sodium aluminum silicate, NaCa4[Al9Si27O72]·28H2O)

Dalmatian Jasper

Feldspar porphyry (Microcline and Quartz with Arfvedsonite spots)

Cobalt Glass Slug (Man-made Glass)

Amorphous Silica with Cobalt Oxide (SiO2 + CoO)

Amber

Succinates (C10H16O)

Amber

Succinite (organic fossilized resin)