Crystals
Bismuth
Chemical element 83 Symbol Bi Trigonal-rhombohedral structure Strong diamagnetism Melting point approximately 271.4 °C Thin-film interference color Mohs approximately 2–2.5 Density approximately 9.78 g/cm³ Bismuth: Elemental Metal, Hopper Geometry, and...
Bismuth
Chemical element 83 Symbol Bi Trigonal-rhombohedral structure Strong diamagnetism Melting point approximately 271.4 °C Thin-film interference color Mohs approximately 2–2.5 Density approximately 9.78 g/cm³ Bismuth: Elemental Metal, Hopper Geometry, and...
Bornite
Copper–iron sulfide Cu5FeS4 Orthorhombic at room temperature Mohs approximately 3 Approximately 63.3% copper by mass Iridescent tarnish Porphyry, vein, skarn, and supergene settings Bornite: Copper-Rich Sulfide, Peacock Tarnish, and the...
Bornite
Copper–iron sulfide Cu5FeS4 Orthorhombic at room temperature Mohs approximately 3 Approximately 63.3% copper by mass Iridescent tarnish Porphyry, vein, skarn, and supergene settings Bornite: Copper-Rich Sulfide, Peacock Tarnish, and the...
Apatite
Apatite mineral group Ca5(PO4)3(F,Cl,OH) Hexagonal crystal system Mohs 5 Fluorapatite, hydroxylapatite, and chlorapatite Gem, biological, geological, and industrial importance Apatite: Phosphate Crystals, Neon Color, and the Mineral Architecture of Bones...
Apatite
Apatite mineral group Ca5(PO4)3(F,Cl,OH) Hexagonal crystal system Mohs 5 Fluorapatite, hydroxylapatite, and chlorapatite Gem, biological, geological, and industrial importance Apatite: Phosphate Crystals, Neon Color, and the Mineral Architecture of Bones...
Aragonite
Calcium carbonate mineral CaCO3 Orthorhombic crystal system Polymorph of calcite Mohs 3.5–4 Specific gravity approximately 2.93–2.95 Shells, pearls, coral, caves, and marine sediment Aragonite: Calcium Carbonate in Starbursts, Cave Coral,...
Aragonite
Calcium carbonate mineral CaCO3 Orthorhombic crystal system Polymorph of calcite Mohs 3.5–4 Specific gravity approximately 2.93–2.95 Shells, pearls, coral, caves, and marine sediment Aragonite: Calcium Carbonate in Starbursts, Cave Coral,...
Angelite
Blue massive anhydrite CaSO4 Orthorhombic calcium sulfate Mohs approximately 3–3.5 Three prominent cleavages near 90° Dry storage and gentle handling Angelite: Powder-Blue Anhydrite, Right-Angled Cleavage, and the Memory of Evaporated...
Angelite
Blue massive anhydrite CaSO4 Orthorhombic calcium sulfate Mohs approximately 3–3.5 Three prominent cleavages near 90° Dry storage and gentle handling Angelite: Powder-Blue Anhydrite, Right-Angled Cleavage, and the Memory of Evaporated...
Ammonite
Extinct marine cephalopods Subclass Ammonoidea Early Devonian to end Cretaceous Originally aragonitic chambered shells Calcite, pyrite, silica, and internal molds Ammolite from preserved iridescent shell Ammonites: Chambered Cephalopods, Fossil Sutures,...
Ammonite
Extinct marine cephalopods Subclass Ammonoidea Early Devonian to end Cretaceous Originally aragonitic chambered shells Calcite, pyrite, silica, and internal molds Ammolite from preserved iridescent shell Ammonites: Chambered Cephalopods, Fossil Sutures,...