Banded Jasper / Rhyolite (Picture Jasper)
Silicified Rhyolitic Tuff / Microcrystalline Quartz (SiO2)
igneous
Category
Sedimentary (Volcanic)
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Chalcedony
SiO2 (Silicon Dioxide)
mineral
Polished black stone, possibly black jasper or obsidian
Uncertain; candidates include microcrystalline quartz (SiO₂; black jasper) or volcanic glass (obsidian, SiO₂)
mineral
Jasper (Chert / Chalcedony)
Silicon Dioxide (SiO2) with Iron Oxide inclusions
mineral
Polymict breccia
Volcanic breccia (clast-rich pyroclastic rock), compositionally likely andesitic to basaltic
igneous
Red jasper
Microcrystalline quartz (chalcedony), SiO₂, colored mainly by iron oxides
mineral
Vesicular basalt (likely scoria)
Basaltic volcanic rock; chiefly plagioclase, pyroxene, and olivine, with vesicles formed by trapped gas
igneous
Tuffaceous sandstone or volcanic tuff
Lithic/feldspathic tuffaceous sandstone; composition likely quartz, feldspar, volcanic ash, and lithic fragments
sedimentary
Quartz (Chert / Agate / Chalcedony)
Silicon Dioxide (SiO2)
mineral
Agate
Silicon Dioxide (Chalcedony), SiO2
gemstone
Polymictic conglomerate
Clast-supported conglomerate, typically quartz- and feldspar-rich in a dark matrix
sedimentary
Red Jasper (Tumbled)
Silicon Dioxide (SiO2) with iron oxide inclusions
sedimentary
Carnelian
Carnelian (Silica, SiO2)
mineral
Tumbled Stone Collection (Fluorite, Sodalite, Moss Agate, Amethyst/Charoite, and Grey Agate)
Silica (SiO2) and Calcium Fluoride (CaF2) based minerals
mineral
Geode
Crystalline Quartz in Sedimentary Matrix (SiO2)
sedimentary
Red Jasper
Silicon Dioxide (SiO2) - variety Jasper
mineral
Blue Lace Agate
Silicon Dioxide (SiO2) - Chalcedony / Quartz
sedimentary
Weathered porous sandstone or tuff
Indeterminate siliciclastic rock, likely quartz-rich sandstone; possibly volcanic tuff
sedimentary
Yellow Jasper Sphere
Microcrystalline Quartz (SiO2 with iron oxide/hydroxide impurities)
sedimentary
Jasper
Silicon dioxide (SiO2)
mineral
Black Onyx
Silicon Dioxide (SiO2) - Chalcedony
gemstone
Yellow Jade (or Carnelian / Chalcedony)
SiO2 (Silicon Dioxide)
mineral
Basalt pebble
Basalt; fine-grained mafic volcanic rock, chiefly plagioclase and pyroxene with possible olivine
igneous
Tumbled Agate
Silicon Dioxide (SiO2)
gemstone
Bumble Bee Jasper
Calcite and Volcanic Ash Mixture
sedimentary
Jasper
Microcrystalline quartz ($SiO_2$)
sedimentary
Agate Geode
Silicon Dioxide (SiO2) - Chalcedony variety
sedimentary
Jasper or Agate Nodule
SiO2
mineral
Polished/tumbled brecciated jasper
Silica-rich microcrystalline quartz (chalcedony), commonly with iron-oxide minerals and assorted lithic fragments
sedimentary
Celadonite in Basalt (Green Earth)
Celadonite (K(Mg,Fe2+)(Fe3+,Al)Si4O10(OH)2)
mineral
Porphyritic volcanic rock, likely porphyritic andesite
Porphyritic andesite; chiefly plagioclase and pyroxene/amphibole phenocrysts in a fine volcanic groundmass
igneous
Rounded weathered pebble
Likely fine-grained sandstone, siltstone, or weathered volcanic rock; exact identification is uncertain from the image
sedimentary
Quartz Geode Fragment
Silicon Dioxide (SiO2)
mineral
Weathered vesicular volcanic rock, likely scoria
Scoria (vesicular basaltic-andesite), compositionally dominated by plagioclase, pyroxene, and iron-rich glass
igneous
Quartz Druze on Matrix
Silicon Dioxide (SiO2)
mineral
Common Opal in Host Rock
Hydrated Silica (SiO2·nH2O)
mineraloid
Red Jasper
Silicon Dioxide (SiO2) with Iron impurities
mineral
Weathered basalt or mafic volcanic rock
Basalt; typically plagioclase feldspar, clinopyroxene, and often olivine or iron oxides
igneous
Jasper
Microcrystalline Quartz (SiO2)
mineral
Common Opal
Hydrated amorphous silica (SiO2·nH2O)
mineral
Chalcedony (Agate/Common Opal blend)
Microcrystalline Quartz (SiO2)
mineral
Pink Opal
Hydrated silica (SiO2 "n H2O)
mineral