Chert (Iron-stained)
Microcrystalline quartz (SiO2)
Category
Browse synthetic or natural fiber specimens identified by the Rock Identifier community.
Chert (Iron-stained)
Microcrystalline quartz (SiO2)
Sandstone (likely Arkose or Quartz Sandstone)
Arenite (SiO2 + varied clasts)
Chert (often called Flint or River Rock)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (with Quartz Vein)
Microcrystalline silica (SiO2)
Asphalt Concrete (Bituminous Concrete)
Bituminous aggregate
White Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
Crinoid Columnal Fossil
Class Crinoidea (Echinodermata); usually calcite replacement (CaCO3)
Carnelian
Carnelian (SiO2)
Green Sandstone
Glauconitic Sandstone
Chert (Iron-stained)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Pumice
Pumice (Vitreous pyroclastic rock)
Carnelian Agate
Silicon dioxide (SiO2) - Chalcedony variety
Labradorite
(Ca, Na)(Al, Si)4O8
Fossilized Coral (Petoskey Stone or similar)
Hexagonaria percarinata (Order: Rugosa)
Carnelian Agate
Silicon Dioxide (SiO2)
Quartzite with Quartz Veining
Quartzite (primarily SiO2)
Dendritic Agate
Silicon Dioxide (SiO2) with Manganese or Iron Oxide inclusions
Limonite (Iron Ore)
Hydrated Iron(III) Oxide-Hydroxide (FeO(OH)·nH2O)
Scoria (Lava Rock)
Scoria
Fossil Shark Tooth
Carcharodon sp. (likely Otodus or similar Lamniformes order)
Sandstone (Ferruginous)
Arenite (primarily SiO2 with iron oxide cement)
Dendritic Quartz
Silicon Dioxide (SiO2) with Manganese/Iron oxide inclusions
Vesicular Basalt (Scoria)
Basalt (Vesicular)
Quartzite Pebble
Metamorphic Quartzite (SiO2)
Sodalite
Sodalite (Na8(Al6Si6O24)Cl2)
Siltstone Pebble
Siltstone
Amethyst
SiO2 (Silicon Dioxide with iron impurities)
River Quartzite Pebble
Quartzite (SiO2)
Cobalt Glass Slug (Cullet)
Man-made Silicate Glass with Cobalt Oxide (CoO)
Milky Quartz
Silicon Dioxide (SiO2)
Ruby in Zoisite
Anyolite (combination of Ca2Al3(SiO4)3(OH) and Al2O3:Cr)
Banded Calcite (often sold as Caribbean Calcite or Mexican Onyx)
Calcium Carbonate (CaCO3)
Green Jasper
Jasper (Silicates, SiO2)
Green Jasper
Silicon Dioxide (SiO2) with impurities
Porous Quartzite
Metamorphosed Quartz-rich Sandstone (SiO2)
Quartz-veined Siltstone
Siltstone with Quartz (SiO2) veins
Apache Tear (Obsidian)
Volcanic glass (SiO2 - Silicon Dioxide)
Amazonite
Amazonite (Microcline) - K(AlSi3O8)
Jasper with Iron Inclusions
Silicon Dioxide (SiO2) with impure Iron Oxides
Druzy Chalcedony/Quartz on Fluorite core
Silicon Dioxide (SiO2) on Calcium Fluoride (CaF2)
Limonite (Iron Ore)
Limonite (FeO(OH)·nH2O)
Red Jasper
Silicon Dioxide (SiO2) with Hematite inclusions