Mineral (Chalcedony)

Chalcedony

Silicon Dioxide (SiO2)

Tumbled yellow-orange chalcedony (likely carnelian or honey agate)

Microcrystalline quartz, SiO₂; orange coloration commonly from iron oxides

Yellow Chalcedony

Chalcedony (a cryptocrystalline variety of Quartz, SiO₂)

Tumbled pink chalcedony (likely pink agate)

Chalcedony, microcrystalline SiO₂; variety of quartz

Tumbled chalcedony (likely orange agate/carnelian)

Microcrystalline quartz, SiO₂; chalcedony with iron-oxide coloration

Tumbled chalcedony (likely moss or gray agate)

Microcrystalline quartz, SiO₂; chalcedony/agate variety

Polished honey/brown agate (likely carnelian chalcedony)

Microcrystalline quartz, SiO₂; chalcedony with iron-oxide coloration

Chalcedony

Silicon Dioxide (SiO2)

Chalcedony

Silicon Dioxide (SiO2)

Tumbled honey-brown chalcedony (likely common quartz)

Microcrystalline quartz, SiO₂; possibly iron-stained chalcedony or low-grade agate

Chalcedony in Matrix

Silicon Dioxide (SiO2)

Pink Chalcedony

Silicon Dioxide (SiO2)

Chalcedony or Chert/Jasper with secondary mineral staining

SiO2 (for chalcedony/quartz) with possible secondary copper minerals (e.g., CuSiO3·nH2O for chrysocolla, Cu2(CO3)(OH)2 for malachite) or iron oxides/hydroxides.

Brown chalcedony (likely carnelian or agate fragment)

Microcrystalline quartz, SiO₂; iron-oxide-colored chalcedony

Tumbled orange chalcedony

Chalcedony (microcrystalline quartz, SiO₂), likely orange carnelian

Tumbled pale agate or chalcedony

Microcrystalline quartz (SiO₂), likely agate/chalcedony

Blue chalcedony (probable)

Microcrystalline quartz, SiO₂

Botryoidal chalcedony (possibly common opal)

Microcrystalline quartz, SiO₂; pale portions may include hydrated silica opal, SiO₂·nH₂O

Polished jasper pebble

Microcrystalline quartz (chalcedony), commonly SiO₂, with iron-oxide impurities

Chalcedony (Agate/Chert variety)

Silicon Dioxide (SiO2)

Blue chalcedony (likely dyed or polished)

Chalcedony, microcrystalline quartz (SiO₂)

Chalcedony

Silicon Dioxide (SiO2)

Weathered agate or chalcedony nodule

Microcrystalline quartz (SiO₂), likely chalcedony/agate

Tumbled gray agate/chalcedony (probable)

Microcrystalline quartz, SiO₂; likely banded chalcedony or agate

Chalcedony

Silicon dioxide (SiO2) - Microcrystalline quartz

Chalcedony

Silicon Dioxide (SiO2)

Carnelian

Chalcedony (SiO2)

Chalcedony

Cryptocrystalline Quartz (SiO2)

Chalcedony

Cryptocrystalline Quartz (SiO2)

Chalcedony

Cryptocrystalline Quartz (SiO2)

Chalcedony

Silicon dioxide (SiO2) - Cryptocrystalline Quartz

Chalcedony

Cryptocrystalline Quartz (SiO2)

Yellow chalcedony (possibly jasper/chalcedony)

Microcrystalline quartz, SiO₂; yellow coloration likely from iron oxides/hydroxides

Chalcedony

Chalcedony (cryptocrystalline Silicon Dioxide, SiO2)

Chalcedony

Cryptocrystalline Quartz (SiO2)

Chalcedony

Cryptocrystalline Quartz (SiO2)

Chalcedony

Chalcedony (a microcrystalline variety of Quartz, SiO2)

Chalcedony

Cryptocrystalline Quartz (SiO2)

Iron-stained chalcedony or jasper

Microcrystalline quartz (SiO₂), likely ferruginous jasper/chalcedony

Tumbled/rounded agate (likely mossy or brecciated chalcedony)

Microcrystalline quartz, SiO₂ (chalcedony/agate)

Agate (Puddingstone style)

Silicon Dioxide (SiO2) with impurities

Chalcedony

Silicon Dioxide (SiO2)