Chert (Chalk-associated Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Category
Browse organic (non rock) specimens identified by the Rock Identifier community.
Chert (Chalk-associated Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Moss Agate
Chalcedony (Silicon Dioxide - SiO2) with inclusions
Sandstone
Arenite or Sandstone
Chert (specifically Gray/Tan Bedded Chert)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (variously known as Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Mookaite Jasper
Silicified Radiolarite (Silicon Dioxide: SiO2)
Chert (Nodular Chert)
Microcrystalline Silica (SiO2)
Jasper
Jasper (Silicon Dioxide, SiO2)
Moss Agate
Silicon Dioxide (SiO2) with mineral inclusions
Chert (specifically Flint or Dark Chalcedony)
Silicon Dioxide (SiO2)
Chert / Flint Nodule
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Quartz (Vein Quartz)
Silicon Dioxide (SiO2)
Quartz Geode/Cluster
Quartz (SiO2)
Chert (and Flint)
Silicon Dioxide (SiO2)
Sandstone (likely with Borings or Vesicular Basalt)
Clastic Sedimentary Rock (Sandstone)
Chert (varietal Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Quartzite
Quartzite (SiO2)
Chert (and Flint)
Silicon dioxide (SiO2)
Green Moss Agate
Agate (Silicon Dioxide, SiO2) with inclusions of hornblende or chlorite
Greenstone (possibly Basalt or Greenschist)
Greenschist (composed primarily of chlorite, actinolite, and epidote)
Hypersthene (or Enstatite/Ferrosilite)
Orthopyroxene series (Mg,Fe)SiO3 - specifically, historically hypersthene (intermediate member) now referred to as Enstatite (Mg-rich) or Ferrosilite (Fe-rich)
Chert (specifically Tan Chert or Flint)
Silicon Dioxide (SiO2)
Mookaite Jasper
Silicified Radiolarite (SiO2)
Chert / Flint
Cryptocrystalline quartz (SiO2)
Chert (Smoky variety)
Microcrystalline Quartz (SiO2)
Chert (often called Flint or River Stone)
Chert (Microcrystalline Silicon Dioxide, SiO2)
Conglomerate
Conglomerate
Chert (Flint)
Microcrystalline Quartz (SiO2)
Chert (Nodule)
Silicon dioxide (SiO2) - Cryptocrystalline Quartz
Almandine Garnet in Schist
Almandine, Fe3Al2(SiO4)3
Chert (Iron-stained)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Sandstone
Quartz Arenite (a common type of sandstone, given the appearance), Arkose, Greywacke (depending on mineralogy)
Green Moss Agate
Silicon Dioxide with inclusions (SiO2 + Mn/Fe)
Chert (Flint)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Chert (Chalcedony/Jasper)
Microcrystalline Quartz (SiO2)
Moss Agate
Chalcedony (Silicon Dioxide, SiO2) with dendritic inclusions
Quartzite
Quartzite (primarily SiO2)
Chert (Iron-stained)
Microcrystalline Quartz (SiO2)
Moss Agate
Chalcedony (SiO2) with inclusions of manganese or iron oxides
Chert (variations include Flint or Jasper)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Purple Agate (Dyed Chalcedony)
SiO2 (Silicon Dioxide) with organic dyes
Moss Agate
Chalcedony (SiO2) with inclusions of manganese or iron oxide