Mineral_variety_of_chalcedony

Chalcedony (likely common gray chalcedony)

Microcrystalline quartz, SiO₂

Agate

Chalcedony (SiO2)

Jasper with Quartz

Silicon dioxide (SiO2)

Polished agate pebble (likely dyed or naturally banded chalcedony)

Chalcedony, microcrystalline SiO₂; agate is banded chalcedony

Yellow Chalcedony

Chalcedony (a cryptocrystalline variety of Quartz, SiO₂)

Polished agate/geode slab

Banded chalcedony (microcrystalline quartz, SiO₂), likely with quartz crystals

Tumbled blue-green stone, likely dyed agate

Agate (microcrystalline quartz, SiO₂); blue coloration may be artificial

Tumbled chalcedony (likely agate or jasper)

Microcrystalline quartz, SiO₂ (chalcedony)

Red Jasper

Silicon Dioxide (SiO2) with iron oxide inclusions

Tumbled orange chalcedony or carnelian

Cryptocrystalline quartz, SiO₂; likely carnelian variety

Likely red-and-green jasper (rough pebble)

Microcrystalline quartz (SiO₂), colored by iron oxides; exact identification requires testing

Banded Calcite

Calcite (Calcium Carbonate, CaCO3)

Green Jasper

Jasper (Silicon Dioxide, SiO2)

Brown chalcedony/agatic jasper nodule

Microcrystalline quartz (SiO₂), likely iron-stained chalcedony with included or weathered host material

Tumbled chalcedony or agate

Microcrystalline quartz (SiO₂), likely pale agate/chalcedony

Chalcedony on Matrix

Silicon Dioxide (SiO2)

Honey-colored chalcedony (likely carnelian)

Microcrystalline quartz, SiO₂; orange chalcedony colored by iron oxides

Blue Chalcedony

Silicon Dioxide (SiO2)

Chalcedony (Agate)

Silicon Dioxide (SiO2)

Tumbled jasper (likely brown jasper)

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

Dalmatian jasper (polished stone beads)

Commercial “Dalmatian jasper”; typically a feldspar-rich rock with dark aegirine or arfvedsonite inclusions, not true jasper

Botryoidal chalcedony (possibly common opal)

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

Chalcedony

Cryptocrystalline Quartz (SiO2)

Chalcedony (Agate/Chert variety)

Silicon Dioxide (SiO2)

Tumbled brown chalcedony/jasper

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

Tumbled Yellow Chalcedony / Iron-Stained Quartz

Silicon Dioxide (SiO2)

Chalcedony (variations like Agate or Jasper)

Chalcedony (SiO₂ - microcrystalline quartz)

Tumbled jasper or iron-rich chert

Microcrystalline quartz (SiO₂), likely colored by iron oxides

Polished orbicular jasper (likely ocean jasper)

Silicified microcrystalline quartz (SiO₂), with iron-oxide and other mineral inclusions; exact variety cannot be confirmed from the image

Yellow Agate

Silicon Dioxide (SiO2)

Blue chalcedony (likely dyed or polished)

Microcrystalline quartz, SiO₂ (chalcedony variety)

Chalcedony (Agate/Carnelian)

Cryptocrystalline Silicon Dioxide (SiO2)

Yellow Agate

Silicon Dioxide (SiO2)

Agate Slab

Chalcedony (SiO2)

Tumbled chalcedony (likely blue-gray agate)

Cryptocrystalline quartz, SiO₂; chalcedony/agate variety

Red jasper (likely tumbled)

Microcrystalline quartz, chiefly SiO₂, colored red by iron oxides

Jasper

Chalcedony (SiO2)

Tumbled brown chalcedony or jasper

Microcrystalline quartz, SiO₂; possibly iron-bearing jasper

Chalcedony (Agate / Moss Agate)

Silicon Dioxide (SiO2)

Chalcedony (likely carnelian/agate beads or rounded grains)

Microcrystalline quartz, SiO₂; chalcedony varieties

Polished agate (likely chalcedony)

Microcrystalline quartz, SiO₂; agate is banded chalcedony

Jasper / Chert (river tumbled)

Microcrystalline Quartz (SiO2)