Tumbled Stones (various)
Mixed Silica-based Minerals (primarily Quartz and Chalcedony)
Category
Browse sedimentary (silicified fossiliferous chalcedony) specimens identified by the Rock Identifier community.
Tumbled Stones (various)
Mixed Silica-based Minerals (primarily Quartz and Chalcedony)
Carnelian Agate
Chalcedony (Silicon Dioxide, SiO2) with Iron Oxide impurities
Carnelian
Carnelian (a variety of Chalcedony, which is a microcrystalline quartz, SiO₂)
Bloodstone (Heliotrope)
Chalcedony (SiO2) with inclusions of Iron Oxide or Red Jasper
Mixed Gemstone Bracelet
Mixed natural minerals and rocks (e.g., Rhodonite, Malachite, Sodalite, Rose Quartz, Black Tourmaline, Quartz/Chalcedony variants)
Carnelian
Carnelian (Silicon Dioxide, SiO2)
Lavender Agate / Chalcedony Sphere
Agate (Microcrystalline Quartz) - SiO2
Grey Agate (Banded Chalcedony)
Agate (Silicon Dioxide - SiO2)
Quartz Pebble (Chalcedony/Agate)
Silicon Dioxide (SiO2)
Vesicular Basalt with Quartz/Chalcedony
Vesicular Basalt (primarily Plagioclase, Pyroxene, and Olivine with SiO2 infill)
Chrysoprase (Nickel-bearing Chalcedony)
Silicon Dioxide (SiO2) with traces of Hydrous Nickel Silicates
Amethyst (Agate/Chalcedony variety)
Silicon Dioxide (SiO2) with iron impurities
Carnelian (Red-Orange Chalcedony)
Silicon Dioxide (SiO2)
Carnelian Agate (with Quartz/Chalcedony)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Brown Jasper (Likely)
Jasper (Cryptocrystalline Silicon Dioxide - SiO2)
Onyx Marble (also commonly called Onyx)
Calcite (CaCO3), often with other mineral impurities
Crazy Lace Agate
Silicon dioxide (SiO2) - a variety of banded Chalcedony (cryptocrystalline quartz)
Sandstone or Siltstone
Arenite (if sandstone)
Carnelian
SiO2 (Silicon Dioxide) - Translucent reddish-brown variety of Chalcedony
Blue Agate (Dyed Chalcedony)
Silicon Dioxide (SiO2)
Riverstone Quartzite / Chalcedony Nugget
Silicon Dioxide (SiO2)
Purple Agate (Dyed Chalcedony)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Banded Agate (specifically Chalcedony nodule)
Agate (Silicon Dioxide, SiO2)
Yellow Quartz (Chalcedony/Citrine Pebble)
Silicon Dioxide (SiO2)
Moss Agate
Chalcedony (Silicon Dioxide, SiO2) with inclusions of Chlorite, Manganese, or Iron
Carnelian Agate
Silicon Dioxide (SiO2) - Chalcedony containing Iron Oxide impurities
Red Jasper (beads)
SiO₂ (Silicon Dioxide)
Shale or Slaty Mudstone
Argillaceous sedimentary rock
Sandstone
Arenite (primarily SiO2)
Chert Breccia
Brecciated Chert (Microcrystalline Silica)
Sandstone (Quartz-rich)
Arenite (SiO2)
Tiffany Stone
Bertrandite (Be4Si2O7(OH)2) mixed with Fluorite (CaF2), Opal, and Chalcedony
Sandstone (with man-made markings)
Arenite (composed primarily of Quartz, SiO2)
Shale (Beach-worn)
Laminated Pelite (primarily clay minerals and quartz)
Druzy Chalcedony/Quartz on Fluorite core
Silicon Dioxide (SiO2) on Calcium Fluoride (CaF2)
Blue Lace Agate (Banded Chalcedony)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Blue Lace Agate (Variety of Chalcedony)
Silicon Dioxide (SiO2)
Sandstone (Picture Sandstone)
Arenite (primarily SiO2)
Mudstone
Lutylite (group of fine-grained sedimentary rocks)
Sandstone (Quartzite-rich)
Clastic sedimentary rock (SiO2 primary)
Sandstone
Arenite
Brown Sandstone
Arenite (primarily Quartz and Feldspar, with Iron Oxide cement)