Mineral (Chalcedony)

Tumbled amber-colored quartz/chalcedony (likely carnelian or honey agate)

Microcrystalline quartz, SiO₂; coloration may derive from iron oxides

Tumbled agate/chalcedony (likely moss or plume agate)

Microcrystalline quartz, SiO₂, chiefly chalcedony with possible iron-oxide inclusions

Tumbled blue chalcedony (likely blue quartz)

Chalcedony, cryptocrystalline SiO₂; possibly chrysoprase or dyed quartz

Red jasper-like chalcedony pebble

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

Yellow Chalcedony (Agate)

Silicon Dioxide (SiO2)

Chalcedony / Agate Nodule

Silicon Dioxide (SiO2)

Geode with Quartz and possibly Jasper/Hematite

Quartz (SiO2) and Chalcedony (cryptocrystalline SiO2), possibly stained by iron oxides

Chalcedony Pebble with Jasper/Iron Oxide Cortex

Silicon Dioxide (SiO2)

Chalcedony (Agate)

Silicon Dioxide (SiO2)

Polished agate or chalcedony pebble

Microcrystalline quartz (SiO₂), likely chalcedony/agate

Blue Chalcedony

Silicon Dioxide (SiO2)

Tumbled carnelian agate

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

Chalcedony (likely brown agate or flint)

Microcrystalline quartz, SiO₂; chalcedony, possibly iron-stained

Tumbled blue chalcedony or pale aquamarine-like quartz

Chalcedony (microcrystalline SiO₂), possibly blue quartz; visual identification is uncertain

Chalcedony (Botryoidal)

Silicon Dioxide (SiO2)

Weathered agate or chalcedony nodule

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

Tumbled chalcedony (likely moss or plume variety)

Microcrystalline quartz, SiO₂

Tumbled yellow-brown jasper or chalcedony

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

Chalcedony Geode / Agate Nodule

Cryptocrystalline Quartz (SiO2)

Dendritic agate or included chalcedony (likely tumbled)

Microcrystalline quartz, SiO₂; inclusions likely manganese-oxide dendrites or iron minerals

Geode (Unopened)

Quartz/Chalcedony concretion

Green agate/geode slab

Cryptocrystalline quartz (chalcedony), SiO₂, likely agate with druzy quartz

Tumbled yellow chalcedony

Microcrystalline quartz (SiO₂), likely yellow jasper or chalcedony

Blue Chalcedony

Silicon Dioxide (SiO2)

Chalcedony (Botryoidal/Chalcedony Rose)

Silicon Dioxide (SiO2)

Jasper

SiO2

Polished brown jasper or chalcedony

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

Tumbled yellow chalcedony (likely honey agate or yellow quartz)

Microcrystalline quartz, SiO₂; coloration likely from iron oxides or included minerals

Tumbled jasper or chalcedony pebble

Microcrystalline quartz, SiO₂ (likely jasper/chalcedony)

Polished ocean jasper (orbicular jasper), likely a small tumbled stone

Microcrystalline quartz/chalcedony, SiO₂, with iron-oxide and other mineral inclusions

Polished yellow-orange stone pendant, possibly carnelian or yellow chalcedony

Chalcedony, microcrystalline quartz (SiO₂); identification from the photo is uncertain

Tumbled agate or chalcedony

Microcrystalline quartz (SiO₂), likely brown/orange chalcedony or agate

Black Onyx

Cryptocrystalline Quartz (SiO2) with impurities

Polished orbicular agate beads

Microcrystalline quartz (SiO₂), chalcedony with orbicular banding

Polished jasper pebble (possibly orbicular jasper)

Microcrystalline quartz (SiO₂), likely jasper; exact variety cannot be confirmed visually

Tumbled banded agate beads

Agate, microcrystalline quartz (SiO₂), a variety of chalcedony

Jasper (likely red/brown jasper pebble)

Microcrystalline quartz (SiO₂), an opaque variety of chalcedony; exact identification is uncertain from the photo

Red jasper (possible polished or dyed stone)

Jasper, an opaque microcrystalline variety of quartz (SiO₂)

Polished red jasper (possibly carnelian/chalcedony)

Jasper, an opaque microcrystalline variety of quartz (SiO₂); exact identification is uncertain from the image

Polished banded agate (likely carnelian agate)

Microcrystalline quartz, SiO₂ (chalcedony); iron-oxide coloring

Agate (specifically, multi-colored or pastel-dyed agate)

Silicon dioxide (SiO2) - specifically, a cryptocrystalline variety of quartz known as Chalcedony, with banding classified as Agate. (If it were Fluorite, the chemical formula would be Calcium Fluoride - CaF2).

Tumbled orange chalcedony or quartzite

Microcrystalline quartz (SiO₂), possibly iron-stained chalcedony; exact identification requires testing