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

Obsidian

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

Dyed blue chalcedony (likely dyed quartz pebble)

Chalcedony, microcrystalline quartz (SiO₂), artificially colored

Smoky Quartz

Silicon Dioxide (SiO2)

Bornite (Peacock Ore)

Bornite (Cu5FeS4)

Red Jasper with Quartz

Silicon Dioxide (SiO2) with Hematite impurities

Tumbled jasper and agate assortment

Microcrystalline quartz (chalcedony), SiO₂, with iron-oxide and other mineral impurities

Polychrome jasper

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

Beach Pebbles and Jasper

Quartz / Microcrystalline Silicon Dioxide (SiO2)

Obsidian (likely)

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

Bismuth

Bismuth (Bi)

Green Glass Slag

Amorphous Silicon Dioxide (SiO2) with metal oxide impurities

Tumbled blue stone, likely blue aventurine or dyed quartzite

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

Red Jasper (Quartz)

SiO2 (Silicon Dioxide with Iron Oxide inclusions)

Tumbled red jasper (probable)

Microcrystalline quartz/chalcedony, SiO₂, colored by iron oxides

Banded river pebble, likely weathered sandstone or mudstone

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

Tumbled fossiliferous limestone

Bioclastic limestone, primarily calcite (CaCO₃)

Snowflake obsidian

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

Tumbled jasper or chert fragment

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

Black obsidian

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

Tumbled chalcedony (likely agate or jasper fragment)

Microcrystalline quartz, SiO₂ (chalcedony)

Tumbled brown stone, possibly jasper or iron-rich quartz

Uncertain; likely microcrystalline quartz (SiO₂) with iron-oxide inclusions

Dyed Blue Agate

Cryptocrystalline Quartz (SiO2)

Blue Agate (Tumbled and Dyed)

Silicon Dioxide (SiO2) with likely organic dyes

Possible basalt pebble

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

Polished jasper, likely orbicular or brecciated jasper

Jasper: microcrystalline quartz (chalcedony), SiO₂, colored by iron oxides and other inclusions

Black obsidian (probable)

Volcanic glass; primarily SiO₂-rich rhyolitic composition

Red Jasper

Silicon Dioxide (SiO2) with iron oxide inclusions

Dark river pebble, likely basalt or fine-grained volcanic rock

Basalt (probable); mostly plagioclase and pyroxene, with possible magnetite

Polished jasper (likely brecciated or red jasper)

Microcrystalline quartz (chalcedony), SiO₂, with iron-oxide pigments and possible breccia fragments

Metallic sulfide mineral fragment, likely bornite or chalcopyrite

Bornite (Cu₅FeS₄) or chalcopyrite (CuFeS₂)

River Jasper (Green Jasper)

Silicon Dioxide (SiO2) with impurities

Red jasper pebble

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

Tumbled black stone, likely basalt or black jasper

Basalt (fine-grained plagioclase–pyroxene rock), possibly opaque microcrystalline quartz/jasper

Brecciated Jasper

Brecciated Jasper (Microcrystalline Quartz / SiO2)

Red jasper (likely polished/tumbled)

Jasper, microcrystalline quartz (SiO₂) colored by iron oxides

Red Jasper (Chert)

Silicon Dioxide (SiO2) with iron oxide inclusions

Weathered sandstone

Quartz-rich clastic sandstone, chiefly SiO₂ with minor feldspar, lithic grains, and iron-oxide/clay cement

Iridescent quartz-bearing rock, likely bornite/chalcopyrite-bearing quartzite

Quartz (SiO₂) with probable chalcopyrite (CuFeS₂) and/or bornite (Cu₅FeS₄)

Likely green obsidian or dark green volcanic glass

Obsidian, a rhyolitic volcanic glass; exact identification requires testing

Tumbled yellow jasper or chert

Microcrystalline quartz (SiO₂), likely iron-stained jasper/chert

Heat-Treated Citrine (Amethyst)

Silicon Dioxide (SiO2) with iron impurities

Jasper with Hematite

Silicon Dioxide (SiO2) with Iron Oxide (Fe2O3)