Sedimentary (If Natural Jasper) Or Artificial (If Slag)

Smoky Quartz

Smoky Quartz (SiO2)

Dark gray rounded stone, possibly basalt or slag

Uncertain; likely fine-grained basalt (plagioclase–pyroxene) or iron-rich industrial slag

Red jasper (likely brecciated or iron-stained jasper)

Jasper, microcrystalline quartz (SiO₂), colored chiefly by iron oxides

Peacock ore

Iridescent chalcopyrite, commonly marketed as bornite

Tumbled dark green stone, likely serpentine or greenstone

Serpentinite (hydrated magnesium silicate minerals, chiefly antigorite/lizardite); possible chlorite-rich greenstone

Orange chalcedony or weathered quartz pebble

Microcrystalline quartz, SiO₂; possibly iron-oxide-stained chalcedony

Heat-Treated Amethyst (Commercial Citrine)

Silicon Dioxide (SiO2) with iron impurities

Mystic Topaz

Al2SiO4(F,OH)2 (Coated)

Dyed blue chalcedony (likely dyed agate or quartzite)

Chalcedony, microcrystalline SiO₂; blue color likely artificial dye

Dyed Agate

Silicon Dioxide (SiO2) - Chalcedony variety

Small dark rock fragment

Uncertain; possibly weathered basalt or slag

Dyed Howlite

Borosilicate hydroxide (Ca2B5SiO9(OH)5)

Iron-rich slag or weathered ironstone fragments

Probably hematite–goethite material; possibly industrial iron slag (Fe₂O₃/FeO(OH))

Blue-green glassy mineral specimen, possibly chalcedony or slag glass

Uncertain; candidate minerals include chrysocolla-bearing chalcedony or copper-bearing glassy slag

Jasper / Chert (river tumbled)

Microcrystalline Quartz (SiO2)

Possible weathered basalt or iron-rich slag

Basalt, tentatively; composition likely plagioclase and pyroxene with possible magnetite

Mixed polished river stones

Likely quartz, quartzite, chert/jasper, and possibly limestone or marble

Chert (Jasper variety)

Microcrystalline Quartz (SiO2)

Dark rounded pebble, possibly basalt

Basalt (fine-grained mafic volcanic rock; identification tentative from photograph)

Iron-rich basalt or weathered ironstone

Basalt, likely variolitic/vesicular and coated with iron oxides; composition mainly plagioclase, pyroxene, and magnetite/hematite

Iron-rich vesicular rock, possibly weathered scoria or ironstone

Likely oxidized basaltic scoria (Fe-oxide-bearing volcanic rock); exact identification requires testing

Red jasper / iron-rich chert

Microcrystalline quartz (SiO₂) colored by hematite/goethite

Dyed Agate Slice

Silicon Dioxide (SiO2) - Cryptocrystalline Quartz

Synthetic Resin (Artificial Specimen)

Polyurethane or Polyester Resin

Iron-rich chert or jasper fragment

Microcrystalline quartz (SiO₂), colored by iron oxides/hydroxides

Green Slag Glass

Amorphous Silica / Glassy Blast Furnace Slag

Heat-Treated Citrine (Amethyst)

Silicon Dioxide (SiO2) with iron impurities

Scoria (vesicular volcanic rock)

Basaltic scoria; chiefly plagioclase, pyroxene, olivine, and volcanic glass

Likely yellow quartz gemstone ring

Quartz (SiO₂), possibly heat-treated citrine or lemon quartz; metal setting appears to be brass/gold-colored alloy

Leland Blue Stone

Anthropogenic Iron Smelting Slag

Quartzite with Iron Inclusions

Quartzite (pre d om i n a n t l y SiO2) with H e m a t i t e / G o e t h i t e

Aura Quartz (Coated Quartz)

Silicon Dioxide (SiO2) coated with vaporized metals

Tumbled gabbro or basalt

Dark mafic igneous rock, likely gabbro (plutonic) or basalt (volcanic), composed mainly of plagioclase and pyroxene

Weathered vesicular volcanic rock (likely pumice/tuff)

Porous volcanic pyroclastic rock, probably pumiceous tuff; exact identification requires testing

Vesicular basalt (scoriaceous basalt)

Basalt, chiefly plagioclase feldspar and pyroxene with minor olivine; vesicles formed by trapped volcanic gas

Likely basaltic rock fragment

Fine-grained mafic igneous rock, probably basalt (plagioclase–pyroxene ± olivine)

Polished brown jasper pebble

Jasper, an opaque microcrystalline variety of chalcedony (SiO₂), colored by iron oxides

Heat-Treated Citrine

Silicon Dioxide (SiO2) with iron impurities

Dyed Blue Agate

Silicon dioxide (SiO2) with artificial pigment

Jasper

Microcrystalline Quartz (SiO2)

Slag Glass (Cullet Glass)

Amorphous Silica (Industrial byproduct)

Tumbled jasper (likely picture jasper or iron-rich jasper)

Microcrystalline quartz/chalcedony, SiO₂, colored by iron oxides