Crystals
Sea urchin
Sea Urchin Fossils • Class Echinoidea • calcitic echinoderm tests, spines, jaws, molds, and casts Fossil record • Late Ordovician to Recent Core plan • five ambulacra alternating with five...
Sea urchin
Sea Urchin Fossils • Class Echinoidea • calcitic echinoderm tests, spines, jaws, molds, and casts Fossil record • Late Ordovician to Recent Core plan • five ambulacra alternating with five...
Rutile quartz
Rutilated Quartz • quartz, SiO₂, enclosing acicular crystals of rutile, TiO₂ Needle colors • pale gold, yellow-orange, copper, red-brown, silver-gray, and dark brown Structures • isolated needles, parallel bundles, sagenitic...
Rutile quartz
Rutilated Quartz • quartz, SiO₂, enclosing acicular crystals of rutile, TiO₂ Needle colors • pale gold, yellow-orange, copper, red-brown, silver-gray, and dark brown Structures • isolated needles, parallel bundles, sagenitic...
Shark teeth
Fossil Shark Teeth • mineralized dental remains of sharks and related cartilaginous fishes Crown • highly mineralized enameloid over dentine Root • porous dentine-rich anchoring tissues Fossil color • controlled...
Shark teeth
Fossil Shark Teeth • mineralized dental remains of sharks and related cartilaginous fishes Crown • highly mineralized enameloid over dentine Root • porous dentine-rich anchoring tissues Fossil color • controlled...
Red tiger eye
Red Tiger Eye • chatoyant quartz-rich aggregate with aligned, altered riebeckite-crocidolite fiber trails Trade names • bull’s-eye and ox’s-eye Color • hematite-rich red, rust, brick, and mahogany Optical effect •...
Red tiger eye
Red Tiger Eye • chatoyant quartz-rich aggregate with aligned, altered riebeckite-crocidolite fiber trails Trade names • bull’s-eye and ox’s-eye Color • hematite-rich red, rust, brick, and mahogany Optical effect •...
Quartz with inclusions
Quartz with inclusions • SiO₂ enclosing minerals, fluids, gases, cavities, fractures, and earlier growth surfaces Solid inclusions • rutile, tourmaline, chlorite, hematite, pyrite, titanium oxides Scenic structures • gardens, mosses,...
Quartz with inclusions
Quartz with inclusions • SiO₂ enclosing minerals, fluids, gases, cavities, fractures, and earlier growth surfaces Solid inclusions • rutile, tourmaline, chlorite, hematite, pyrite, titanium oxides Scenic structures • gardens, mosses,...
Oolite
Oolite • sedimentary rock dominated by coated grains called ooids Ooids • commonly about 0.25–2 mm across Classic composition • calcite or aragonite cortices and carbonate cement Related rocks •...
Oolite
Oolite • sedimentary rock dominated by coated grains called ooids Ooids • commonly about 0.25–2 mm across Classic composition • calcite or aragonite cortices and carbonate cement Related rocks •...