Tumbled Black Stone
Unknown, possibly Obsidian, Onyx, or Tourmaline
igneous or mineral
Category
Mineral (Chalcedony)
Browse mineral (chalcedony) specimens identified by the Rock Identifier community.
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Chalcedony (Agate Pebble)
Silicon Dioxide (SiO2)
mineral
Polished agate geode slice
Microcrystalline quartz (chalcedony), SiO₂, with possible quartz-lined or calcite-filled cavity
mineral
Black Onyx
Silicon Dioxide (SiO2)
mineral
Polished orbicular agate (likely ocean jasper)
Microcrystalline quartz, SiO₂; chalcedony with orbicular patterns and possible mineral inclusions
mineral
Plume Agate
Cryptocrystalline Quartz (SiO2)
Mineral/Gemstone
Chalcedony (or a variety of Chalcedony, likely Agate or Jasper)
Chalcedony (SiO₂)
Mineral (or mineraloid if microcrystalline)
Polished banded calcite (onyx marble)
Calcite, CaCO₃; commonly sold as banded calcite or “onyx marble”
mineral
Ocean Jasper
Spherulitic Chalcedony (SiO2)
mineral
Blue Chalcedony
Silicon Dioxide (SiO2) - Microcrystalline Quartz
mineral
Moss Agate with Quartz Druzy
Chalcedony with inclusions (SiO2)
mineral
Polished banded agate
Microcrystalline quartz (SiO₂), chiefly chalcedony
mineral
Jasper
Silicon dioxide, SiO2
Mineral
Tumbled or naturally water-worn chalcedony
Chalcedony, microcrystalline quartz (SiO₂)
mineral
Dragon Blood Jasper
Epidote with Red Piedmontite (silicate)
sedimentary
Polished agate/geode slice
Chalcedony (microcrystalline quartz, SiO₂), likely agate with an altered druzy/quartz interior
mineral
Agate Geode
Chalcedony (cryptocrystalline SiO2)
mineral
Lavender chalcedony (possibly light amethyst) pendant
Chalcedony: microcrystalline quartz, SiO₂; exact identification requires testing
gemstone
Agate
Cryptocrystalline quartz, SiO2
mineral
Chalcedony Geode
Silicon Dioxide (SiO2)
mineral
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Ocean Jasper
Spherulitic Chalcedony (SiO2)
mineral
Blue Chalcedony
Silicon Dioxide (SiO2)
mineral
Jasper and Chalcedony
Silicon Dioxide (SiO2) microcrystalline quartz
sedimentary
Quartz Geode Fragment
Silicon Dioxide (SiO2)
mineral
Agate (Fortification Agate)
Banded Chalcedony (SiO2)
mineral
Tumbled green chalcedony (likely chrysoprase)
Chalcedony, microcrystalline quartz (SiO₂); green color may be from nickel-bearing chrysoprase
mineral
Blue Lace Agate
Chalcedony (SiO2) with trace minerals
mineral
Chalcedony/Agate
Cryptocrystalline Silica (SiO2)
mineral
Chalcedony (Botryoidal)
Silicon Dioxide (SiO2)
mineral
Bloodstone
Chalcedony (cryptocrystalline quartz)
Mineral/Semiprecious Stone
Quartz / Chalcedony
Silicon Dioxide (SiO2)
mineral
Jasper and Chalcedony Composite
Silicon Dioxide (SiO2) microcrystalline quartz
sedimentary
Likely tumbled orange carnelian
Carnelian, orange chalcedony (microcrystalline quartz, SiO₂)
gemstone
Chalcedony (likely agate)
Microcrystalline quartz, SiO₂; agate is banded chalcedony
mineral
Blue Chalcedony
Cryptocrystalline Quartz (SiO2)
mineral
Moss Agate
Chalcedony (SiO2 with inclusions)
mineral
Plume Agate or Moss Agate
Agate (SiO2)
mineral
Polished jasper pendant
Jasper, an opaque microcrystalline variety of quartz (SiO₂); exact variety cannot be confirmed from the image
gemstone
Brown agate (chalcedony)
Microcrystalline quartz, SiO₂; likely iron-stained chalcedony
mineral
Tumbled jasper, likely picture jasper or brecciated jasper
Microcrystalline quartz (SiO₂), chiefly chalcedony with iron-oxide pigments
mineral
Yellow Jasper
Silicon Dioxide (SiO2) with iron oxide inclusions
sedimentary