Sandstone
Arenicola (comprising mostly Quartz, SiO2)
Category
Browse organic mineraloid specimens identified by the Rock Identifier community.
Sandstone
Arenicola (comprising mostly Quartz, SiO2)
Petrified Wood
Silicified Wood (primarily SiO₂)
Jasper (Green/Yellow Moss Jasper)
Silicon Dioxide (SiO2)
Ferruginous Sandstone (Ironstone)
Arenite with Iron-Oxide Cement (FeO(OH)·nH2O / Fe2O3)
Moss Agate
Silicon Dioxide (SiO2) with inclusions
Anthracite Coal
Anthracite (Carbon-rich metamorphic coal)
Petrified Wood
Silicified Wood (SiO2)
Fossiliferous Brachiopod in Shale
Brachiopoda (Phylum) preserved in Carbonaceous Shale
Chert (Field Stone)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Jasper with Quartz Vein
Silicon Dioxide (SiO2) with impurities
Petrified Wood (Silicified Wood)
Silicified Wood / Silicon Dioxide (SiO2)
Chert / Flint
Microcrystalline Quartz (SiO2)
Petrified Wood
Silicified Wood / Chalcedony (SiO2)
Pyrite
Pyrite (Iron sulfide, FeS₂)
Chert (Jasper/Mudstone)
Silicon Dioxide (SiO2)
Chert (Nodule)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (specifically Jasper or Flint variant)
Microcrystalline Quartz (SiO2)
Chert / Flint
Cryptocrystalline Quartz (SiO2)
Chert (White Chert / Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Jasper variety)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Chert (Tan/Buff Chert)
Microcrystalline Quartz (SiO2)
Sandstone Concretion
Clastic sedimentary rock (primarily Quartz SiO2)
Chert / Flint
Cryptocrystalline Quartz (SiO2)
Chert (Flint)
Chert (Microcrystalline Quartz, SiO2)
Chert (often colloquially referred to as Flint)
Chert (Cryptocrystalline Quartz, SiO2)
Petrified Wood
Silicified Wood (SiO2)
Chert (Green variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Petrified Wood
Silicified Wood (primarily SiO₂ - Silicon Dioxide)
Chert (specifically Flint or Gray Chert)
Silicon Dioxide (Microcrystalline Quartz), SiO2
Chert (Iron-stained)
Microcrystalline Quartz (SiO2)
Chert (Nodule)
Chert (primarily Microcrystalline Quartz - SiO2)
Banded Chert
Microcrystalline Quartz (SiO2)
Petrified Wood
Silicified Wood (primarily SiO2 - Silicon Dioxide)
Chert (vuggy variety)
Microcrystalline silica (SiO2)
Chert (Flint)
Chert (Cryptocrystalline Quartz, SiO2)
Sandstone (with carbonaceous plant fragments)
Arenite (composed primarily of SiO2)
Chert (Jasper/Iron-stained Quartzite)
Silicon Dioxide (SiO2)
Chert Pebble (with Quartz Vein)
Chert (Cryptocrystalline Silica - SiO2)
Chert (Iron-stained)
Microcrystalline Quartz (SiO2)
Chert (variations include Flint or Jasper)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Smooth River Pebble)
Silicon Dioxide (SiO2)
Petrified Wood
Silicified Wood (SiO2)