Tektite (Natural Glass)

Yellow Quartz (Polished)

Silicon Dioxide (SiO2) with iron inclusions

Apache Tear

Obsidian (Hydrated Volcanic Glass, SiO2)

Carnelian (orange-red chalcedony)

Chalcedony, microcrystalline quartz (SiO₂), iron-colored variety

Weathered agate or chalcedony nodule

Microcrystalline quartz (SiO₂), likely agate/chalcedony with iron-oxide staining

Tumbled jasper, likely red/brown jasper

Microcrystalline quartz (chalcedony), SiO₂, colored by iron oxides

Red jasper (likely brecciated jasper)

Microcrystalline quartz/chalcedony, SiO₂, colored mainly by iron oxides

Small tumbled dark stone, possibly basalt or slag

Likely fine-grained basalt; exact identification is uncertain from the photograph

Quartz (specifically Milky or Clear Quartz)

Silicon Dioxide (SiO2)

Amethyst

Amethyst (Silicon Dioxide - SiO2 with iron impurities)

Iron-rich slag or limonite-bearing rock

Hydrated iron oxides, chiefly limonite/goethite (FeO(OH)·nH₂O); possibly industrial iron slag

Amethyst

Amethyst (SiO2 with Iron impurities)

Amethyst Geode

Amethyst (Silicon Dioxide), Formula: SiO2

Tumbled chalcedony or carnelian

Microcrystalline quartz (SiO₂), likely iron-bearing chalcedony

Likely purple quartzite or purple chert

Quartzite/chert, predominantly microcrystalline SiO₂; exact identification requires testing

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Banded agate (likely fire agate or iron-stained chalcedony)

Microcrystalline quartz, SiO₂; chalcedony with iron-oxide inclusions

Pyrite

Iron Sulfide (FeS2)

Sandstone

Arenite (Sedimentary rock composed of sand-sized grains, primarily SiO2)

Jasper

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Red Jasper

Silicon Dioxide (SiO2) with Hematite impurities

Jasper with Quartz Vein

Silicon Dioxide (SiO2) with impurities

Red Jasper

Silicon Dioxide (SiO2) with Hematite (Fe2O3) inclusions

Red Jasper (Heliotrope family variant)

Silicon Dioxide with Hematite inclusions (SiO2 + Fe2O3)

Red Jasper

Silicon Dioxide (SiO2) with Hematite impurities

Granite

Granite (Felsic Plutonic Rock)

Quartz Pebble

Silicon Dioxide (SiO2)

Chert or flint fragment

Microcrystalline quartz (SiO₂), likely iron-stained chert

Milky quartz fragment

Quartz (silicon dioxide, SiO₂)

Tumbled carnelian (likely)

Orange-red chalcedony, microcrystalline quartz (SiO₂)

Amethyst (Tumbled/Weathered Quartz)

Amethyst (SiO2 with iron impurities)

Orange calcite

Calcite (CaCO₃)

Likely tumbled jasper or chert specimens

Microcrystalline quartz (SiO₂), commonly jasper/chert; exact identification is uncertain from the photograph

Green aventurine quartz (probable)

Quartz, SiO₂, with fuchsite or other green mica inclusions

Tumbled dark stone, likely basalt or chert

Basalt (fine-grained mafic rock), possibly weathered chert; exact identification requires testing

Citrine

SiO2 (Silicon Dioxide)

Rainbow Fluorite

Fluorite (Calcium Fluoride, CaF2)

Translucent chalcedony (likely agate or common opal)

Microcrystalline quartz, SiO₂; possible hydrated silica opal, SiO₂·nH₂O

Fluorite (Blue)

Calcium Fluoride (CaF2)

Blue chalcedony (likely common blue agate)

Microcrystalline quartz, SiO₂; chalcedony variety

Polished jasper pebble

Jasper, microcrystalline quartz (SiO₂) with iron-oxide and clay-mineral impurities

Amethyst (Tumbled)

Amethyst (Silicon Dioxide with Iron impurities) - SiO2

Red Jasper

Jasper (Silicon Dioxide: SiO2 with Iron oxide inclusions)