Sedimentary (Or Mineraloid)

Polished amber

Amber (fossilized plant resin), commonly succinite; organic mineraloid rather than a true mineral

Tumbled amber-like gemstone

Likely amber (fossilized resin; organic mineraloid), possibly citrine or yellow-brown glass imitation

Fordite

Anthropogenic paint-rock

Amber (likely a small polished amber piece)

Natural fossil resin; amber is an organic mineraloid, not a crystalline mineral. The image alone cannot confirm authenticity.

Orange cabochon gemstone, likely amber or amber-like resin

Natural amber: fossilized plant resin (organic mineraloid), commonly succinite; exact identification requires testing

Precious Coral

Corallium rubrum (Calcium carbonate with trace carotene)

Amber

Succinite (fossilized tree resin)

Opalite

Synthetic Opalite Glass

Slag Glass

Amorphous Silica Glass (with metal oxide inclusions)

Red Coral

Corallium rubrum (Calcium Carbonate, CaCO3 with Carotenoid pigments)

Green Slag

Anthropogenic Silicate Glass

Synthetic Resin (Artificial Specimen)

Polyurethane or Polyester Resin

Iron Slag

Ferrous Slag (Industrial Byproduct)

Slag (Industrial Glass Slag)

Amorphous Silicate Glass (often containing Al, Ca, Mg, and Ti oxides)

Shell Cameo

Cypraecassis rufa (Bullmouth Queen Helmet Shell)

Green Glass (often marketed as 'Obsidian' or 'Green Quartz')

Amorphous Silica (SiO2) with copper or chromium additives

Ferruginous Slag (Iron Smelting Byproduct)

Anthropogenic Vitreous Silicate (often containing Fayalite: Fe2SiO4)

Opaline Glass (Opalite)

Synthetic Silicon Dioxide Glass

Slag (Industrial Glass/Metal Waste)

Artificial silicate/ferro-silicate byproduct

Man-made Crystal (Lead Glass)

Lead oxide-doped Silica Glass (approx. SiO2 + PbO)

Amber

Succinicum (Organic compound, primarily C10H16O)

Tektite (Indochinite)

Tektite (High-silica natural glass)

Amber (and Citrine Quartz)

Succinite (Amber) and Silicon Dioxide (SiO2)

Tektite (specifically Indochinite)

Tektite (Natural silica glass)

Cat's Eye Shell (Shiva Shell)

Operculum of the Turbo petholatus (Tapestry Turban Snail), predominantly Calcium Carbonate (Aragonite)

Ferruginous Slag (Iron Smelting Byproduct)

Fused Silicate Scoria (Amorphous mixture of FeO, SiO2, and CaO)

Opalite

Synthetic Opalized Glass

Amber

Succinite (specifically for Baltic amber); Approximate formula: C10H16O

Cobalt Blue Sea Glass

Amorphous Silica Glass (SiO2 + CoO)

Amber

Succinite (Resinite)

Slag Glass (Cullet)

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

Green Glass Slag

Amorphous Silicon Dioxide (SiO2) with metal oxide impurities

Baltic Amber (Butterscotch variety)

Succinite

Red Slag Glass

Amorphous Silica (Industrial byproduct with metallic oxide dopants)

Opalite

Synthetic Opalized Glass (SiO2 + additives)

Cullet Glass (sometimes mistaken for Blue Obsidian or Slag)

Amorphous Silicon Dioxide (SiO2) with chemical additives (e.g., Cobalt for blue color)

Green Slag Glass

Amorphous Silica / Glassy Blast Furnace Slag

Glass Nugget (Tumbled Glass)

Amorphous Silicon Dioxide (SiO2) with additives

Goldstone (Brown)

Aventurine glass

Fossil-bearing concretion, possibly containing a fossil shell or other organic inclusion

Calcareous concretion; exact fossil and host-rock composition are not identifiable from the image

Fossiliferous Sedimentary Rock

Sedimentary limestone with invertebrate fossil imprint

Sandstone or Siltstone

Arenite (if sandstone)