Crystals
Fulgurite
Fulgurite • natural material fused, melted, or vitrified along a lightning-current path Not a mineral species • commonly a glass-rich geological object Silica-rich examples may contain lechatelierite Classic form: branching...
Fulgurite
Fulgurite • natural material fused, melted, or vitrified along a lightning-current path Not a mineral species • commonly a glass-rich geological object Silica-rich examples may contain lechatelierite Classic form: branching...
Hessonite
Grossular garnet variety Ca3Al2(SiO4)3 Isometric crystal system Mohs approximately 6.5–7 Cinnamon stone Hessonite Garnet: Cinnamon Color, Treacle Light, and the Warm Side of Grossular Hessonite is the apricot-to-cognac variety of...
Hessonite
Grossular garnet variety Ca3Al2(SiO4)3 Isometric crystal system Mohs approximately 6.5–7 Cinnamon stone Hessonite Garnet: Cinnamon Color, Treacle Light, and the Warm Side of Grossular Hessonite is the apricot-to-cognac variety of...
Petrified wood
Fossil wood preserved by mineralization Commonly SiO2: opal, chalcedony, and quartz Growth rings, rays, vessels, and bark may survive Mohs about 6.5–7 when quartz-rich Agate veins and drusy cavities may...
Petrified wood
Fossil wood preserved by mineralization Commonly SiO2: opal, chalcedony, and quartz Growth rings, rays, vessels, and bark may survive Mohs about 6.5–7 when quartz-rich Agate veins and drusy cavities may...