Mineral (Chalcedony)

Agate

SiO2 (Silicon dioxide, cryptocrystalline quartz)

Jasper

Chalcedony (Microcrystalline Quartz) - SiO2

Chrysocolla in Quartz (Gem Silica)

Cu2-xAlx(H2-xSi2O5)(OH)4·nH2O (Chrysocolla) / SiO2 (Quartz)

Red jasper (likely)

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

Yellow jasper (likely polished/tumbled)

Microcrystalline quartz, SiO₂, colored by iron oxides; exact identification is uncertain from the image

Jasper

Silicon dioxide (SiO2)

Jasper

Silicon dioxide (SiO2)

Red Jasper

Silicon Dioxide (SiO2) with Iron Oxide inclusions

Fancy Jasper

Silicon Dioxide (SiO2)

Polished agate slice

Banded chalcedony, microcrystalline SiO₂

Breciated Jasper

Silicon Dioxide (SiO2) with iron oxide inclusions

Tumbled chalcedony (likely mossy/inclusion-rich variety)

Chalcedony, microcrystalline quartz (SiO₂)

Botryoidal chalcedony (possibly agate/geode material)

Chalcedony, microcrystalline quartz (SiO₂)

Tumbled chalcedony pebble

Chalcedony, microcrystalline quartz (SiO₂)

Tumbled chalcedony or quartz-rich chert

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

Jasper (likely brecciated or silicified jasper)

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

Agate

Agate (Cryptocrystalline Quartz, SiO2)

Polished orbicular jasper (likely ocean jasper)

Silicified microcrystalline quartz (SiO₂), commonly called orbicular jasper or ocean jasper

Polished ocean jasper / orbicular jasper

Microcrystalline quartz (SiO₂), commonly with chalcedony, feldspar, and iron/manganese oxides

Polished brown jasper (probable ocean jasper or iron-rich jasper)

Microcrystalline quartz/chalcedony, SiO₂, colored by iron oxides and other inclusions

Tumbled brown jasper

Jasper, microcrystalline quartz (SiO₂), commonly with iron-oxide impurities

Quartz (Chalcedony/Agate)

Silicon Dioxide (SiO2)

Tumbled purple agate (likely amethyst-bearing agate)

Banded chalcedony, a microcrystalline variety of quartz (SiO₂); exact identification is uncertain from the image

Chalcedony (Agate/Carnelian type)

Silicon Dioxide (SiO2)

Banded agate (likely carnelian/chalcedony)

Microcrystalline quartz (SiO₂), chalcedony; banded variety

Blue-green slag glass or chalcedony-like material

Likely industrial glassy slag; exact identification requires testing

Tumbled yellow chalcedony (likely yellow jasper or quartz)

Microcrystalline quartz, SiO₂; probable chalcedony/jasper variety

Tumbled chalcedony pebble

Chalcedony, microcrystalline quartz (SiO₂), possibly cream-colored agate

Tumbled quartz-rich pebble, possibly agate or chalcedony

Microcrystalline quartz (SiO₂), with possible iron-oxide staining

Orange chalcedony or weathered quartz pebble

Microcrystalline quartz, SiO₂; possibly iron-oxide-stained chalcedony

Agate (Water-Worn Pebble)

Silicon Dioxide (SiO2) - Chalcedony

Raw orange chalcedony (carnelian-like)

Chalcedony, microcrystalline quartz (SiO₂), colored by iron oxides

Polished pink agate/chalcedony pebble

Chalcedony (microcrystalline quartz, SiO₂), likely iron-stained agate

Tumbled chalcedony (likely gray/pink chalcedony)

Chalcedony, microcrystalline quartz (SiO₂)

Carnelian

Carnelian (a variety of Chalcedony, SiO2)

Red Jasper Pebble

Silicon Dioxide (SiO2) with Iron Oxide inclusions

Tumbled blue calcite

Calcite (calcium carbonate, CaCO₃)

Agate

Silicon dioxide (SiO2)

Banded Agate

Silicon Dioxide (SiO2)

Agate

Silicon Dioxide (SiO2)

Jasper Pendant

Chalcedony (Quartz) - SiO2

Blue Dyed Agate

Chalcedony (Silicon Dioxide, SiO2)