Manufactured Glass

Cut quartz crystal (likely rock crystal)

Quartz, silicon dioxide (SiO₂), trigonal crystal system

White/green translucent tumbled mineral fragment

Likely calcite (CaCO₃), possibly fluorite (CaF₂) or glass-like feldspar; visual identification is uncertain

Clear quartz crystal (likely quartz fragment)

Quartz, silicon dioxide (SiO₂)

Goldstone

Not a natural mineral or rock. It is an ornamental glass.

Polished black stone sphere (likely black basalt or black tourmaline)

Most likely fine-grained basalt (plagioclase–pyroxene); mineral identification is uncertain from the image alone

Tumbled blue-green stone, possibly dyed turquoise or chrysocolla

Uncertain; turquoise is hydrated copper aluminum phosphate, CuAl₆(PO₄)₄(OH)₈·4H₂O

Likely polished black stone or obsidian

Obsidian (volcanic glass), chiefly SiO₂

Polished black stone, likely black obsidian

Obsidian — volcanic glass, chiefly SiO₂

Tumbled greenstone / altered basalt pebble

Fine-grained mafic volcanic rock, likely basalt or greenstone; commonly composed of plagioclase, pyroxene, chlorite, epidote, and iron oxides

Green Sea Glass

Man-made vitreous material (silica glass)

Polished black stone, likely black obsidian

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

Green calcite (likely)

Calcite, CaCO₃

Clear quartz pebble or glass-like quartz specimen

Quartz (silicon dioxide, SiO₂)

Beaded blue-and-green gemstone jewelry

Likely dyed or treated chalcedony/agate and green aventurine or glass-like stone; exact identification requires testing

Gray chalcedony or quartz fragment

Microcrystalline quartz, SiO₂ (tentative)

Polished black stone, likely hematite

Hematite (Fe₂O₃), possibly magnetite or a hematite-rich ironstone

Polished black gemstone, likely obsidian

Volcanic glass; primarily silica-rich rhyolitic composition (approximately SiO₂)

Polished black star-shaped stone, likely black obsidian

Obsidian (volcanic glass), primarily SiO₂

Polished black obsidian

Volcanic glass; predominantly rhyolitic silica (SiO₂), with minor iron, magnesium, and alkalis

Likely obsidian (possibly tektite or slag glass)

Volcanic glass; primarily SiO₂, noncrystalline

Leopard jasper (orbicular jasper)

Silicified volcanic rock, chiefly microcrystalline quartz/chalcedony (SiO₂) with feldspar and iron-oxide inclusions

Likely flint/chert fragments

Microcrystalline quartz (SiO₂), possibly fossil-bearing chert

Black tourmaline (likely schorl), polished

Schorl tourmaline — NaFe²⁺₃Al₆(BO₃)₃Si₆O₁₈(OH)₄

Quartz

Silicon Dioxide (SiO2)

Polished blue calcite sphere (tentative identification)

Calcite, CaCO₃; blue color generally results from trace impurities or inclusions

Black tumbled stone, possibly obsidian

Obsidian (volcanic glass; predominantly SiO₂), identification uncertain from image

Opalite

Synthetic Opalised Glass

Polished black stone, likely black obsidian

Obsidian, volcanic glass; primarily silica-rich SiO₂ with minor feldspar, iron, and magnesium

Polished black stone, likely black obsidian

Obsidian (volcanic glass; predominantly SiO₂)

Black tumbled stone, likely obsidian

Volcanic glass (obsidian), primarily amorphous SiO₂

Blue glass-like tumbled specimen

Most likely cobalt-blue slag glass or manufactured glass; not confidently identifiable as a natural mineral from the image

Tumbled granite (likely biotite granite)

Granite: quartz + feldspar + biotite/hornblende

Polished black obsidian

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

Quartz Pebble

Silicon Dioxide (SiO2)

Tumbled black stone, likely obsidian

Obsidian (natural volcanic glass; mainly silica-rich rhyolitic composition)

Feldspar (Plagioclase / Potassium Feldspar)

Feldspar Group (KAlSi3O8 - NaAlSi3O8 - CaAl2Si2O8)

Sandstone

Clastic Sedimentary Rock

Clear Quartz

Silicon Dioxide (SiO2)

Likely obsidian (black volcanic glass)

Obsidian; predominantly rhyolitic volcanic glass, mainly SiO₂

Sandstone

Arenite (SiO2 primarily)

Polished black obsidian pyramid/block

Obsidian — natural volcanic glass, chiefly rhyolitic silica (approximately 70–75% SiO₂)

Tumbled obsidian

Volcanic glass; chiefly silica-rich rhyolitic glass (approximately 70–80% SiO₂)