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

Red Jasper with Quartz

Silicon Dioxide (SiO2) with Hematite impurities

Red Jasper (Quartz)

SiO2 (Silicon Dioxide with Iron Oxide inclusions)

Chert with Chalcedony/Quartz Vug

Cryptocrystalline Silica (SiO2)

Rounded basalt cobble

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

Obsidian

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

Obsidian (likely)

Volcanic glass, predominantly silica-rich rhyolitic composition (no fixed mineral formula)

Smoky Quartz

Silicon Dioxide (SiO2)

Tumbled dark stone, possibly river pebble or hematite

Uncertain; candidates include hematite (Fe₂O₃), basalt, or dark chert

Snowflake obsidian

Volcanic glass (silica-rich rhyolitic composition), commonly with cristobalite inclusions

Red jasper (likely polished or dyed)

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

Beach Pebbles and Jasper

Quartz / Microcrystalline Silicon Dioxide (SiO2)

Tumbled blue stone, likely blue aventurine or dyed quartzite

Quartz (SiO₂), likely with inclusions or artificial dye; exact identification requires testing

Bornite (Peacock Ore) / Acid-treated Chalcopyrite

Bornite (Cu5FeS4) or Chalcopyrite (CuFeS2)

Blue aventurine (likely dyed quartzite)

Quartz-rich quartzite, primarily silicon dioxide (SiO₂); identification is uncertain from the image

River Jasper (Green Jasper)

Silicon Dioxide (SiO2) with impurities

Likely tumbled orange-brown jasper or chert

Microcrystalline quartz (SiO₂), probably iron-oxide-bearing jasper

Polished/tumbled brecciated jasper

Silica-rich microcrystalline quartz (chalcedony), commonly with iron-oxide minerals and assorted lithic fragments

Red Jasper (Chert)

Silicon Dioxide (SiO2) with iron oxide inclusions

Polychrome jasper

Microcrystalline quartz (chalcedony), SiO₂, colored by iron oxides and other inclusions

Banded Agate / Jasper (Chert Pebble)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Smoky quartz-bearing rock

Smoky quartz (SiO₂), possibly in a pegmatitic or quartz-rich matrix

Copper-bearing quartz/rock fragment with attached mica

Chalcopyrite-bearing quartz or altered igneous rock; attached flake likely muscovite or biotite mica

Black obsidian

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

Polished pink gemstone, likely dyed quartz or chalcedony

Uncertain from image; possibilities include dyed quartz (SiO₂) or chalcedony (microcrystalline SiO₂)

Jasper with Hematite

Silicon Dioxide (SiO2) with Iron Oxide (Fe2O3)

Turquoise-colored stone bead necklace

Likely turquoise (CuAl₆(PO₄)₄(OH)₈·4H₂O), but the bead may be dyed or another blue-green stone

Tumbled jasper or chert fragment

Microcrystalline quartz (SiO₂), likely jasper/chert with iron-oxide staining

Brecciated Jasper

Brecciated Jasper (Microcrystalline Quartz / SiO2)

Iridescent bismuth crystal

Bismuth (Bi), commonly laboratory-grown and oxide-coated

Dyed green agate pendant

Microcrystalline quartz (chalcedony), SiO₂; likely dyed agate

Smoky quartz (likely faceted cabochon or rough fragment)

Quartz, silicon dioxide (SiO₂), smoky variety colored by irradiation-related defects

Smoky Quartz

Silicon Dioxide (SiO2) with aluminum impurities

Polished banded jasper (likely ocean jasper or brecciated jasper)

Microcrystalline quartz/chalcedony, SiO₂, with iron-oxide impurities

Red Jasper

Silicon Dioxide (SiO2) with iron oxide inclusions

Red jasper pebble

Jasper, opaque microcrystalline quartz (SiO₂), colored mainly by iron oxides

Tumbled red jasper (probable)

Microcrystalline quartz/chalcedony, SiO₂, colored by iron oxides

Possible basalt pebble

Fine-grained mafic volcanic rock, commonly basalt (plagioclase, pyroxene, minor olivine/iron oxides)

Tumbled chalcedony (likely agate or jasper fragment)

Microcrystalline quartz, SiO₂ (chalcedony)

Black obsidian (probable)

Volcanic glass; primarily SiO₂-rich rhyolitic composition

Banded river pebble, likely weathered sandstone or mudstone

Indeterminate lithic clast; probable quartz-rich sandstone or iron-stained mudstone

Agate

Agate (Silicon Dioxide, SiO2)

Likely green obsidian or dark green volcanic glass

Obsidian, a rhyolitic volcanic glass; exact identification requires testing