Mineral (Chalcedony Variety)

Polished yellow chalcedony pendant (possibly yellow agate)

Microcrystalline quartz, SiO₂; chalcedony variety

Tumbled chalcedony (likely moss or plume variety)

Microcrystalline quartz, SiO₂

Polished jasper (likely brecciated or red jasper)

Microcrystalline quartz (chalcedony), SiO₂, with iron-oxide pigments and possible breccia fragments

Red jasper (likely iron-rich chert)

Microcrystalline quartz, SiO₂, colored mainly by hematite/goethite

Red jasper (probable)

Microcrystalline quartz/chalcedony (SiO₂) colored by iron oxides

Tumbled jasper or iron-rich chert

Microcrystalline quartz (SiO₂), likely colored by iron oxides

Polished brecciated jasper (likely septarian or iron-rich jasper)

Microcrystalline quartz (chalcedony), SiO₂, with iron oxides and possibly calcite or other rock fragments

Jasper

Silicon dioxide (SiO2)

Green Jasper / Chalcedony

Silicon Dioxide (SiO2)

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

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

Red jasper

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

Polished carnelian (likely brecciated agate) heart

Microcrystalline quartz, SiO₂; chalcedony with iron-oxide coloration

Chalcedony (or a variety of Chalcedony, likely Agate or Jasper)

Chalcedony (SiO₂)

Chalcedony with Quartz

Silicon Dioxide (SiO2)

Polished brown agate (likely)

Microcrystalline quartz, SiO₂ (chalcedony; agate variety)

Red Jasper

Silicon Dioxide (SiO2) with Hematite inclusions

Agate (Chalcedony)

Silicon Dioxide (SiO2)

Red jasper (likely)

Jasper, an opaque microcrystalline variety of quartz (SiO₂), colored by iron oxides

Tumbled carnelian (likely)

Cryptocrystalline quartz, SiO₂; reddish chalcedony colored mainly by iron oxides

Tumbled brown agate (probable)

Microcrystalline quartz, SiO₂ (chalcedony/agate)

Tumbled orange chalcedony (probable carnelian)

Cryptocrystalline quartz, SiO₂; reddish-orange variety commonly called carnelian

Tumbled red jasper (likely)

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

Tumbled jasper

Microcrystalline quartz (SiO₂), commonly iron-oxide-bearing chalcedony

Polished agate/geode fragment

Microcrystalline quartz (chalcedony), SiO₂, with possible calcite or quartz cavity lining

Tumbled banded agate beads

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

Tumbled agate or chalcedony

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

Blue Chalcedony

Cryptocrystalline Quartz (SiO2)

Jasper

Chalcedony (SiO2)

Tumbled brown agate/chalcedony (probable)

Microcrystalline quartz, SiO₂; likely iron-stained agate or jasper

Flower Agate

Silicon Dioxide (SiO2) with Chalcedony inclusions

Tumbled jasper (likely picture/brecciated jasper)

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

Tumbled blue chalcedony (possibly blue agate)

Microcrystalline quartz, SiO₂; chalcedony variety

Polished jasper pebble

Microcrystalline quartz (chalcedony), usually with iron-oxide impurities

Tumbled carnelian agate

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

Polished banded agate pendant

Agate, microcrystalline quartz (SiO₂), a chalcedony variety

Polished agate (likely moss or plume agate)

Microcrystalline quartz (SiO₂), chalcedony variety; exact variety is uncertain from the photo

Iron-stained chalcedony or jasper

Microcrystalline quartz (SiO₂), likely ferruginous jasper/chalcedony

Tumbled brown jasper

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

Polished jasper pebble

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

Yellow Chalcedony

Cryptocrystalline Quartz (SiO2)

Polished jasper (likely brecciated or scenic jasper)

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

Tumbled blue chalcedony/agate (likely glassy silica material)

Microcrystalline quartz, SiO₂; possibly blue chalcedony or dyed agate