Brachiopod Fossil (Spiriferid)
Order Spiriferida (Phylum Brachiopoda); mineralized as Calcite (CaCO3) or Chert (SiO2)
sedimentary (fossilized organic remain)
Category
Synthetic Or Natural Fiber
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Smoky Quartz
Silicon Dioxide (SiO2)
mineral
Dyed Howlite (often sold as 'Turquenite')
Calcium Borosilicate Hydroxide (Ca2B5SiO9(OH)5)
mineral
Moonstone (Feldspar variety)
Orthoclase Feldspar (KAlSi3O8)
mineral
Chert Conglomerate (or Breccia)
Sedimentary Clastic Rock (variety: Ferruginous Chert Breccia)
sedimentary
Sandstone
Arenite (SiO2 primarily)
sedimentary
Black Spinel
Magnesium Aluminum Oxide (MgAl2O4)
mineral
Smoky Quartz
Silicon Dioxide (SiO2)
mineral
Smoky Quartz
Quartz (Silicon Dioxide) - SiO2
mineral
Smoky Quartz
Smoky Quartz (SiO2)
mineral
Asphalt Concrete
Bituminous Concrete
sedimentary (artificial)
Mahogany Obsidian
Volcanic Glass (predominantly SiO2 with Hematite/Magnetite inclusions)
igneous
Red Amber (Burmite/Cherry Amber)
Succinite / Retinite (Organic Fossilized Resin, C10H16O)
Mineraloid (Organic)
Bornite
Bornite (Cu5FeS4)
mineral
Tumbled Stone Collection (featuring Tiger's Eye, Rose Quartz, and Moss Agate)
Mixed Silicates and Oxides (predominantly SiO2 group minerals)
mineral
Pink Granite
Granite (Phaneritic intrusive igneous rock)
igneous
Concrete fragment with Aggregate
Anthropogenic Concrete with Calcarious and Siliceous Aggregate
sedimentary (anthropogenic/man-made)
Agate
Silicon Dioxide (SiO2)
mineral
Granite
Granite (Phaneritic Acid Igneous Rock)
igneous
Emerald In Matrix
Beryl (Be3Al2Si6O18) with trace Chromium/Vanadium
mineral
Emerald (Tumbled Beryl)
Beryllium Aluminum Silicate (Be3Al2Si6O18) with Chromium/Vanadium impurities
mineral
Quartz with Iron Staining
Silicon Dioxide (SiO2)
mineral
Smoky Quartz occurring with Feldspar
Silicon Dioxide (SiO2) with Potassium Aluminum Silicate (KAlSi3O8)
mineral
Conglomerate
Conglomerate (Detrital Sedimentary Rock)
sedimentary
Smoky Quartz (Herkimer-style)
Silicon Dioxide (SiO2)
mineral
River Rock (Mossy)
Stream-rounded Clast (likely Siltstone or Sandstone with bryophytes)
sedimentary
River Pebble (likely Quartzite or Chert)
Silicon Dioxide (SiO2)
metamorphic or sedimentary
Howlite
Calcium borosilicate hydroxide (Ca2B5SiO9(OH)5)
mineral
Ambergris
Ambergris (Coprolite-adjacent/Organic secretion)
mineraloid
Tufa
Calcium carbonate (CaCO3) - Porous Limestone
sedimentary
Sandstone (Arkose/Quartzose)
Arenite (SiO2 based clastic rock)
sedimentary
Shale (or Mudstone)
Siltstone/Argillite (composed mainly of clay and silt-sized particles)
sedimentary
Dalmation Stone (Dyed)
Peralkaline rhyolite
igneous
Titanium Aura Quartz
Silicon Dioxide (SiO2) coated with Titanium and Niobium
mineral
Sandstone
Arenite (SiO2 primarily)
sedimentary
Green Aventurine
Silicon Dioxide (SiO2) with Fuchsite inclusions
metamorphic
Piddock bored rock (Boring Stone)
Ichnofossil-bearing Limestone or Mudstone (trace fossils by Pholadidae)
sedimentary
Granite
Granite (composed of Quartz, Feldspar, and Mica/Amphibole)
igneous
Sandstone (with Iron Staining)
Clastic Sedimentary Rock (primarily SiO2 with Fe2O3 oxides)
sedimentary
Chiastolite (Andalusite)
Al2SiO5
metamorphic
Citrine (Heat-Treated Amethyst)
Silicon Dioxide (SiO2)
mineral
Sandstone
Arenite (SiO2-rich)
sedimentary