Tektite (Natural Glass)

Amethyst on Matrix

Amethyst (Silicon Dioxide, SiO2) with impurities of iron and irradiation

Amethyst (Polished/Carved Crystal)

Silicon Dioxide (SiO2) with trace Iron (Fe)

Smoky Quartz (with Druzy/Polished Edge)

Smoky Quartz (Silicon Dioxide, SiO2)

Dark gray rounded stone, possibly basalt or slag

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

Red Jasper

Microcrystalline Quartz (SiO2) with iron oxide inclusions

Red Jasper

Microcrystalline Quartz (Chalcedony), SiO2

Rose Quartz

Silicon Dioxide (SiO2)

Jasper

Jasper (Silicon Dioxide, SiO2)

Yellow Jasper

Silicon Dioxide (SiO2) with iron oxide inclusions

Jasper

Silicon dioxide (SiO2)

Jasper with Quartz inclusions

Silicon Dioxide (SiO2) - Microcrystalline Chalcedony

Jasper

Silicon dioxide (SiO2) with impurities

Jasper with Iron Staining

Silicon Dioxide (SiO2) with Iron Oxide (Fe2O3) impurities

Yellow Jasper

Silicon Dioxide (SiO2) with iron oxide inclusions

Jasper

Jasper (Silicon Dioxide, SiO2)

Red Jasper

Silicon dioxide (SiO2) with iron oxide inclusions

Collection of Minerals and Ores

Various (e.g., Uraninite (U3O8), Carbon (C), Native Gold (Au), Hematite (Fe2O3), Galena (PbS), etc.)

Blue Sapphire (in a faceted jewelry setting)

Corundum (Al2O3) with trace Iron and Titanium

Amethyst (Raw Quartz)

Silicon Dioxide (SiO2) with iron impurities

Citrine

Silicon Dioxide (SiO2) with iron impurities

Amethyst Geode

Silicon Dioxide (SiO2) with iron impurities

Smoky Quartz (Herkimer-style)

Silicon Dioxide (SiO2)

Polished brecciated jasper pebble

Microcrystalline quartz (SiO₂), with iron-oxide inclusions

Tumbled black stone, likely basalt or black jasper

Probably basalt (fine-grained plagioclase–pyroxene rock); exact identification is uncertain from the image

Ferruginous Quartz

Silicon Dioxide (SiO2) with Hematite/Limonite impurities

Smoky Quartz

Silicon Dioxide (SiO2)

Granite

Granite

Ferruginous Quartz

Silicon Dioxide with Iron Oxide inclusions (SiO2 + Fe2O3)

White chalcedony or quartz-rich pebble

Microcrystalline quartz (SiO₂), possibly with minor calcite or feldspar

Weathered quartz-rich pebble

Likely quartz-bearing granite or granitic gneiss; exact identification requires testing

Polished/tumbled quartz-rich pebble, possibly jasper or quartzite

Indeterminate; likely microcrystalline quartz (SiO₂), potentially iron-stained jasper or quartzite

Amethyst

Silicon dioxide (SiO2) with iron impurities

Quartzite

Quartzite (mostly SiO2)

Weathered quartz-rich pebble

Milky quartz, chiefly silicon dioxide (SiO₂), possibly with iron-oxide staining and minor feldspar

Citrine and Quartz

Silicon Dioxide (SiO2)

Blue Quartz

Silicon Dioxide (SiO2) with microscopic inclusions

Yellow Quartz

Silicon Dioxide (SiO2)

Quartz (Iron-stained)

Silicon Dioxide (SiO2)

Sandstone (Ferruginous)

Arenite (SiO2 with Fe2O3 inclusions)

Sandstone

Arenite (composed primarily of SiO2)

Sandstone

Arenite (SiO2-rich)

Quartz with Iron Staining

Silicon Dioxide (SiO2)