Mineral (Chalcedony)

Tumbled agate and chalcedony specimens

Microcrystalline quartz (SiO₂), chiefly chalcedony/agate

Tumbled orange chalcedony or jasper

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

Tumbled orange chalcedony (likely carnelian)

Microcrystalline quartz, SiO₂; iron-bearing variety commonly termed carnelian

Polished yellow-green chalcedony (likely serpentine or quartz pebble)

Microcrystalline quartz, SiO₂ (if chalcedony); possible antigorite/lizardite, Mg₃Si₂O₅(OH)₄ (if serpentine)

Botryoidal chalcedony with quartz vug

Microcrystalline quartz, SiO₂ (chalcedony), with a drusy quartz-lined cavity

Polished gray agate or chalcedony

Microcrystalline quartz (SiO₂), likely gray chalcedony/agate

Agate

Chalcedony (SiO2)

Agate

Chalcedony (SiO2)

Iron-rich jasper (likely rough jasper/chert)

Microcrystalline quartz (SiO₂), colored by iron oxides

Tumbled jasper (likely brecciated or mahogany jasper)

Microcrystalline quartz/chalcedony, SiO₂, with iron-oxide inclusions

Bloodstone

Heliotrope (Chalcedony)

Chalcedony on Matrix

Silicon Dioxide (SiO2)

Chalcedony (Agate)

Silicon Dioxide (SiO2)

Tumbled blue chalcedony

Chalcedony, microcrystalline quartz (SiO₂)

Geode half

Geode (often quartz/chalcedony based)

Chalcedony (Agate)

Silicon Dioxide (SiO2)

Amber-colored chalcedony (carnelian), possibly amber

Chalcedony: microcrystalline quartz (SiO₂); amber: fossilized tree resin

Quartz geode

Silica (SiO₂), commonly chalcedony-lined quartz geode

Polished chrysoprase (likely)

Chalcedony, microcrystalline quartz (SiO₂), colored by nickel-bearing minerals

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

Pink chalcedony or weathered pink quartzite

Microcrystalline quartz (SiO₂), possibly iron-bearing chalcedony

Tumbled brown chalcedony (likely carnelian/agatesque material)

Microcrystalline quartz, SiO₂; chalcedony variety

Chalcedony with Quartz Crystals

Silicon Dioxide (SiO2)

Chalcedony (Common Opal or Agate variant)

Silicon dioxide (SiO2) with trace hydration

Chalcedony (Moonstone-like Agate)

Silicon Dioxide (SiO₂)

Quartz geode

Microcrystalline and crystalline quartz (SiO₂), likely chalcedony-lined geode

Blue glassy tumbled stone, likely blue chalcedony or slag glass

Chalcedony (microcrystalline SiO₂), possibly man-made blue glass

Polished carnelian jasper / brecciated jasper

Microcrystalline quartz (SiO₂), chalcedony with iron-oxide pigments and opaque jasper fragments

Chalcedony (Agate / Moss Agate)

Silicon Dioxide (SiO2)

Blue Chalcedony

Chalcedony (cryptocrystalline Silicon Dioxide, SiO2)

Tumbled agate or chalcedony

Microcrystalline quartz (SiO₂), likely agate/chalcedony with green inclusions

Tumbled orange chalcedony or carnelian

Cryptocrystalline quartz, SiO₂; likely carnelian variety

Tumbled brown chalcedony/jasper

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

Tumbled Yellow Chalcedony / Iron-Stained Quartz

Silicon Dioxide (SiO2)

Tumbled orange-and-white chalcedony/agate

Microcrystalline quartz (SiO₂), likely iron-stained chalcedony or carnelian-bearing agate

Tumbled yellow chalcedony or quartz

Chalcedony (microcrystalline SiO₂), possibly iron-stained quartz

Pink opal and dendritic agate bead bracelet/necklace

Common opal (hydrated amorphous silica, SiO₂·nH₂O) with dendritic agate/chalcedony (microcrystalline quartz, SiO₂)

Blue Lace Agate

Chalcedony (SiO2)

Agate (Chalcedony)

Silicon Dioxide (SiO2)

Mixed Chalcedony and Jasper Bracelet (possibly 'Ocean Jasper' or similar banded variety for brown beads, and blue/grey Chalcedony for the translucent beads)

Chalcedony (SiO2), Jasper (SiO2 with impurities)

Tumbled red-and-cream jasper

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