Anthropogenic Material (Man Made Rock)

Rock crystal (clear quartz), possibly cloudy quartz

Quartz, silicon dioxide (SiO₂)

Weathered iron-rich concretion or ironstone nodule

Goethite–hematite limonite concretion (FeO(OH), Fe₂O₃, and hydrated iron oxides)

Quartz pebble (Quartztite fragment)

Silicon Dioxide (SiO2)

Sandstone (with Liesegang rings or joints)

Clastic Sedimentary Rock (primarily Quartz with Iron Oxide cement)

Clear quartz sphere

Quartz (silicon dioxide, SiO₂)

Tumbled milky quartz pebble

Quartz (silicon dioxide, SiO₂), likely milky quartz

Likely tumbled or cut quartz/chalcedony fragment

Silicon dioxide (SiO₂), probably microcrystalline quartz or quartz

Opalite

Man-made Synthetic Glass (Silicon Dioxide with metal additives)

Blue opalite glass (likely man-made)

Opalite glass; a silica-based amorphous glass, not natural opal

Polished labradorite sphere

Labradorite, calcic plagioclase feldspar ((Ca,Na)(Al,Si)₄O₈)

Citrine Quartz

Citrine (Silicon Dioxide, SiO2)

Chert Concretion

Chert (Microcrystalline Quartz, SiO2)

Opalite

Man-made Opalized Glass (Synthetic Glass)

Slag

Metallurgical Slag

Pyrite in Quartz (Drill Core)

Silicon Dioxide (SiO2) with Iron Sulfide (FeS2) inclusions

Opalite (likely man-made opalescent glass)

Opalite; not a true mineral, typically synthetic opalescent glass (silica-based)

Diamond / Clear Quartz / Glass paste

Carbon (Diamond) / Silicon Dioxide (Quartz)

Goldstone

Aventurine glass (Synthetic glass with copper inclusions)

Conglomerate

Conglomerate Rock (Paraconglomerate)

Opalite

Synthetic Opalite Glass

Tumbled milky quartz pebble

Quartz (silicon dioxide, SiO₂)

Polished brown jasper (likely brecciated or orbicular jasper)

Microcrystalline quartz/chalcedony, SiO₂, with iron-oxide and other mineral inclusions

Cherry Quartz with Rose Quartz

Crystalline Quartz (SiO2) with glass-based synthetic components

Sandstone Anvil / Nutting Stone

Quartzose Sandstone (Sedimentary Rock)

Goldstone

Aventurine Glass (Man-made glass with copper inclusions)

Aura Quartz

Titanium-coated Silicon Dioxide (SiO2)

Tumbled clear quartz (rock crystal)

Quartz, silicon dioxide (SiO₂)

Opalite (Man-made Glass)

Synthetic Silicon Dioxide Glass (SiO2 + metal oxides)

Slag Glass

SiO2 (Silicon Dioxide) with impurities

Man-made Metal Pin (Non-geological)

Antimony-Lead Alloy or Zinc/Brass Base with Electroplating

Possible tektite or iron-rich slag-like natural specimen

Uncertain; possibly natural glass (tektite) or magnetite-rich rock

Opalite (likely imitation opal glass)

Man-made opalescent glass; not a natural mineral (often sold as opalite)

Moldavite

Tektite (Impact Glass), ~80% SiO2 + Al2O3

Clear quartz tumbled stone

Quartz (silicon dioxide, SiO₂)

Small greenish crystal/mineral fragment

Indeterminate; possibly olivine, quartz, or a green gemstone fragment

Opalite (Synthetic Opalized Glass)

Synthetic Silicon Dioxide (SiO2) glass

Opalite crescent pendant

Opalite (man-made opalescent glass; not a natural mineral)

Possible obsidian or slag glass

Volcanic glass, primarily SiO₂; alternatively industrial iron-rich glassy slag

Opalite

Synthetic Opalite Glass / Opalized Glass

Carborundum (Silicon Carbide)

Silicon carbide (SiC)

Sea Glass (White/Clear)

Amorphous Silica (Alkali-Lime-Silica Glass), SiO2 + Na2O + CaO

Asphalt concrete

Anthropogenic conglomerate