Ferruginous Sandstone (Iron-rich Sandstone)
Ferruginous Arenite
Category
Browse mineral description (anthropogenic material) specimens identified by the Rock Identifier community.
Ferruginous Sandstone (Iron-rich Sandstone)
Ferruginous Arenite
Quartzite (Yellow/Tan)
Metamorphic Rock composed of Quartz (SiO₂)
Quartzite
Quartzite (primarily SiO2)
Yellow Jasper
Silicon Dioxide (SiO2) with Goethite/Iron oxide impurities
Basalt
Extrusive mafic igneous rock
Chert / Flint
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Basalt with Peridotite Inclusion
Mafic Volcanic Rock (Extrusive Igneous) with Ultramafic Xenolith
Quartzite
Metamorphosed Quartz Sandstone (SiO2)
Coquina
Biogenic Limestone (Calcium Carbonate - CaCO3)
Quartzite
Quartzite (primarily SiO2)
Limestone
Calcium Carbonate (CaCO3)
Red Jasper
Jasper (a variety of Chalcedony, SiO₂)
Anthracite Coal
Anthracite (high-rank coal)
Quartzite
Quartzite (SiO2)
Coquina
Coquina (Bioclastic Limestone)
Quartzite
Quartzite (primarily SiO2)
Limestone
Calcium Carbonate (CaCO3)
Chert (and Flint)
Cryptocrystalline Quartz (SiO2)
Basalt
Basalt (Aphanitic Mafic Igneous Rock)
Granite (likely a river or beach pebble)
Granite (a felsic intrusive igneous rock primarily composed of quartz, feldspar, and mica)
Green Jasper (with Quartz veining)
Jasper (Silica-rich microcrystalline variety of Quartz), formula: SiO2
Polished Chert (Flint)
Silicon Dioxide (SiO2)
Chert (often called Flint for dark variants)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (and Jasper blend)
Chert (Microcrystalline Quartz, SiO2)
Chert (varietal: Jasper or Flint)
Silicon Dioxide (SiO2) - Cryptocrystalline Quartz
Travertine (used in construction, not a 'specimen' in situ)
Travertine
Ambergris (Geological/Organic Specimen)
Ambra grisea (Produced by Physeter macrocephalus)
Talc
Talc (Mg₃Si₄O₁₀(OH)₂)
Quartz
Quartz (SiO₂ - Silicon Dioxide)
Jade
There are two distinct minerals classified as Jade: Jadeite (Na(Al,Fe3+)Si2O6) and Nephrite (Ca2(Mg,Fe)5Si8O22(OH)2). Based on the image showing translucent, somewhat fibrous material, it is likely Nephrite.
Red Swirl Beads (Likely Resin or Glass, simulating Red Jasper or Agate)
N/A (for the beads as pictured); Red Jasper: SiO2 (Chert variety); Red Agate: SiO2 (Chalcedony variety)
Obsidian
Volcanic glass (high silica content based on SiO2)
Opalite (Man-made Glass)
Fused glass (typically made of dolomite and metal opacifiers)
Jasper (Red/Yellow)
Silicon Dioxide (SiO2) with impurities
Chert or Flint (polished/water-worn)
Chert (a microcrystalline or cryptocrystalline variety of quartz, SiO2). Flint is a specific variety of chert.
Jasper (specifically variegated or swamp jasper beads)
Silicon Dioxide (SiO2) - Cryptocrystalline Quartz
Chert (specifically Flint or Jasper variant)
Microcrystalline or Cryptocrystalline Silicon Dioxide (SiO2)
Anthracite Coal
Anthracite
Quartzite
Quartzite (primarily SiO2)
Chert (Lightly weathered variety)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Chert (Grey-Green Flint)
Microcrystalline silicon dioxide (SiO2)
Quartzite
Quartzite (primarily SiO2)