Antropogenic (Man Made Glass Byproduct)

Clear quartz crystal point

Quartz (silicon dioxide, SiO₂), likely a polished or cut crystal

Orange Calcite

Calcium Carbonate (CaCO3)

Vesicular volcanic rock, likely weathered pumice or scoria

Pumice/scoria; predominantly volcanic glass and feldspar, with possible iron oxides

Obsidian

Volcanic Glass (SiO2)

Chalcanthite

Hydrated copper(II) sulfate (CuSO4·5H2O)

Quartzite

Quartzite (primarily SiO2)

Polished carnelian (reddish-brown chalcedony)

Carnelian, a microcrystalline variety of quartz (SiO₂)

Mahogany Obsidian

Obsidian with Hematite inclusions (SiO2 + Fe2O3)

Quartz-bearing granite or gneiss fragment

Granite/gneiss composed mainly of quartz (SiO₂), feldspar, and minor mica or ferromagnesian minerals

Quartz (White/Milky Pebble)

Silicon Dioxide (SiO2)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Coal

Carbonaceous sedimentary rock

Quartz (Iron-stained)

Silicon Dioxide (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Garnet (Almandine/Pyrope series)

Garnet Group - X3Y2(SiO4)3

Clear quartz cabochon

Quartz (silicon dioxide, SiO₂)

Massive Quartz

Silicon dioxide (SiO2)

Likely obsidian (possibly tektite or slag glass)

Volcanic glass; primarily SiO₂, noncrystalline

Quartzite

Metamorphosed Quartz Sandstone (SiO2)

Green glass-like cabochon, likely synthetic glass or resin

Unidentified green transparent material; possibly molded glass, synthetic spinel, or resin

Polished brown mineral fragment, likely quartz-rich iron-stained material

Possibly quartz (SiO₂) with iron-oxide inclusions; exact identification is uncertain from the image

Orange Quartzite

Metamorphic Quartzite (primarily SiO2)

Milky Quartz

Quartz (Silicon Dioxide - SiO2)

Iron-rich chert or jasper fragment

Microcrystalline quartz (SiO₂), commonly hematite/goethite-bearing

Quartzite (River Cobble)

Quartzite (predominantly SiO2)

Chert (Agate/Flint variant)

Microcrystalline Quartz (SiO2)

Tumbled red jasper

Jasper, microcrystalline quartz (SiO₂) with iron-oxide inclusions

Rhodonite

Rhodonite (MnSiO3)

Clear quartz crystal fragments

Quartz (silicon dioxide, SiO₂)

Milky Quartz

Silicon Dioxide (SiO2)

Quartzite Pebble

SiO2 (Silicon Dioxide)

Milky Quartz

Silicon Dioxide (SiO2)

Iron Slag (Industrial Byproduct)

Anthropogenic pyrometallurgical residue

Yellow Calcite

Calcium Carbonate (CaCO3)

Quartz (Milky Quartz)

Silicon Dioxide (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Tumbled milky quartz

Quartz, silicon dioxide (SiO₂)

Milky Quartz

Silicon Dioxide (SiO2)

Quartz Geode Fragment with Iron Staining

Silicon Dioxide (SiO2)

Likely polished garnet fragment

Garnet group, possibly almandine (Fe₃Al₂Si₃O₁₂)

Quartzite

Quartzite (SiO2)

Quartz crystal cluster

Quartz (silicon dioxide, SiO₂)