Coquina
Coquina (a type of limestone)
Category
Browse not a rock (synthetic material) specimens identified by the Rock Identifier community.
Coquina
Coquina (a type of limestone)
Opalite
Synthetic Glass (SiO2 + impurities)
Silicon Carbide (Carborundum)
Moissanite (SiC), though mostly synthetic
Biotite Mica
K(Mg,Fe2+)3(Al,Fe3+)Si3O10(OH,F)2
Chert / Flint
Chert (varieties include Flint)
Amazonite
KAlSi3O8 (Potassium Feldspar, variety of Microcline)
Jade
Jadeite or Nephrite
Serpentinite (Serpentine Rock)
Serpentinite is a rock composed of one or more serpentine group minerals, chiefly antigorite, chrysotile, and lizardite, with the general formula (Mg,Fe)3Si2O5(OH)4. Often includes other minerals like magnetite, talc, and chromite.
Travertine (used in construction, not a 'specimen' in situ)
Travertine
Serpentinite (Serpentine Rock)
Primarily composed of serpentine group minerals, such as antigorite, chrysotile, and lizardite. Chemical formula for serpentine minerals is (Mg,Fe)3Si2O5(OH)4.
Basalt
Basalt
Lapis Lazuli
Lapis Lazuli (Complex silicate rock containing Lazurite (Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2, Pyrite, and Calcite)
Quartzite
Quartzite (primarily SiO2)
Clear Quartz (Rock Crystal)
Quartz (SiO₂)
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)
Quartz (pebble)
Quartz (SiO₂)
Serpentine
Serpentinite (rock), Serpentine group minerals (e.g., Antigorite, Lizardite, Chrysotile)
Ferruginous Sandstone
Sandstone, Iron-rich
Schist
Schist
Chert (varieties include Flint or Jasper)
Chert (cryptocrystalline quartz; SiO₂)
Serpentinite
Serpentinite
Banded Jasper (Chert)
Silicon Dioxide (SiO2) - variety of Chalcedony
Quartz (chalcedony variety) or Limestone with Quartz Veins
SiO2 (for Quartz/Chalcedony); CaCO3 (for Limestone)
Cobalt Glass Slug (Man-made Glass)
Amorphous Silica with Cobalt Oxide (SiO2 + CoO)
Quartz (likely a weathered/tumbled piece)
Quartz (SiO₂)
Coal (most likely Bituminous or Anthracite)
Bituminous Coal (Grade of Coal), Anthracite (Grade of Coal)
Chert
Chert (microcrystalline quartz)
Dyed Alum or Dyed Quartz (Ornamental Crystal)
Silicon Dioxide (SiO2) or Potassium Alum [KAl(SO4)2·12H2O]
Cubic Zirconia (CZ)
Zirconium dioxide (ZrO2)
Conglomerate
Conglomerate
Red Jasper
Jasper (a variety of Chalcedony, SiO₂ with iron oxide inclusions)
Quartz (likely Milky Quartz)
Quartz (SiO₂ - Silicon Dioxide)
Biotite Mica
Biotite (K(Mg,Fe)3AlSi3O10(F,OH)2)
Quartz (likely Jasper or Chert variety)
Quartz (SiO₂)
Quartz with Iron Stains
Quartz (SiO2) with iron oxide/hydroxide staining
Diamond
Diamond (carbon allotrope), C (chemical formula)
Puddingstone (Jasper Conglomerate)
Conglomerate (specific type: Jasper Conglomerate or Hertfordshire Puddingstone)
Diamond (or Cubic Zirconia)
Crystallized Carbon (C) for Diamond; Zirconium Dioxide (ZrO2) for CZ
Muscovite Mica
Muscovite (KAl₂(AlSi₃O₁₀)(F,OH)₂))
Ruby
Corundum (Al2O3 with Chromium)
Agate
Chalcedony (cryptocrystalline quartz)
Jasper
Silicon Dioxide (SiO2)