Man Made Glass

Blue Goldstone

Man-made glass with suspended copper, cobalt, or manganese particles

Sea Glass

Amorphous silicon dioxide (Man-made glass weathered by nature)

Tumbled milky quartz

Quartz — silicon dioxide (SiO₂), cryptocrystalline or microcrystalline variety possible

Sea Glass

Amorphous Silicon Dioxide (Man-made glass weathered by nature)

Polished black stone, likely black obsidian

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

Milky quartz

Quartz (silicon dioxide, SiO₂)

Sea Glass (White/Clear)

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

Green Aventurine

Silicon Dioxide (SiO2) with inclusions of Fuchsite (K(Al,Cr)2AlSi3O10(OH)2)

Polished labradorite sphere

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

Polished labradorite pendant

Labradorite, a calcium-rich plagioclase feldspar (approximately NaAlSi₃O₈–CaAl₂Si₂O₈)

Tumbled milky quartz

Quartz (SiO₂), cryptocrystalline-to-massive variety

Cullet Glass (Man-made Glass Slag)

Amorphous Silica (SiO2) with chemical additives

Blue opal heart cabochon

Common opal, hydrated amorphous silica (SiO₂·nH₂O), likely blue-dyed or synthetic opalite

Tumbled milky quartz pebble

Quartz (silicon dioxide, SiO₂), opaque-to-translucent milky variety

Green Aventurine

SiO2 (Silicon Dioxide with Fuchsite inclusions)

Quartz (likely milky quartz or quartz glass-like fragment)

Quartz, silicon dioxide (SiO₂)

Tumbled clear quartz (rock crystal)

Quartz, silicon dioxide (SiO₂)

Cobalt Glass Slug (Man-made Glass)

Amorphous Silica with Cobalt Oxide (SiO2 + CoO)

Polished brown jasper (likely brecciated or orbicular jasper)

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

Blue cabochon, likely dyed or synthetic material

Undetermined; possibly dyed chalcedony (SiO₂), glass, or synthetic corundum

Blue-green cabochon, likely chalcedony or treated glass imitation

Cryptocrystalline quartz (chalcedony/possibly chrysoprase); identification uncertain from image

Green Quartz / Chrysoprase / Sea Glass

Silicon Dioxide (SiO2)

Tumbled white chalcedony (likely milky quartz)

Chalcedony, microcrystalline quartz (SiO₂)

Clear quartz crystal (likely)

Quartz, silicon dioxide (SiO₂)

Clear quartz sphere

Quartz (silicon dioxide, SiO₂)

White quartz pebble or chip

Quartz (silicon dioxide, SiO₂), possibly milky quartz

Unidentified translucent crystal/mineral fragment

Likely quartz (SiO₂), but visual identification is uncertain

Green Aventurine

Silicon Dioxide (Quartz with Fuchsite inclusions), SiO2

Polished dendritic agate or jasper

Microcrystalline quartz (SiO₂), likely chalcedony with iron/manganese dendrites

Clear quartz fragment

Quartz (silicon dioxide, SiO₂)

Tumbled milky quartz pebble

Quartz (silicon dioxide, SiO₂)

Tumbled milky quartz (likely)

Quartz, silicon dioxide (SiO₂)

Milky quartz (likely rough quartz crystal)

Quartz, silicon dioxide (SiO₂)

Sea Glass

Amorphous silicon dioxide (SiO2) - Man-made glass tumbled by nature

Polished black pebble, likely basalt

Basalt, a fine-grained mafic volcanic rock composed mainly of plagioclase feldspar and pyroxene, commonly with olivine

Blue obsidian-like volcanic glass

Volcanic glass, chiefly silica-rich amorphous material (composition uncertain)

Milky quartz (likely quartz crystal fragment)

Quartz, silicon dioxide (SiO₂)

Black Obsidian

Amorphous volcanic glass (SiO2 + impurities)

Blue glassy fragment among beach gravel

Likely cobalt-blue man-made glass; not a natural mineral specimen

Green Sea Glass

Amorphous Silica (man-made glass), SiO2 + additive metal oxides

Purple glassy pebble, possibly slag glass

Unidentified; likely man-made glass rather than a natural mineral

Opalite

Synthetic Opalised Glass