Amethyst
Amethyst (Silicon Dioxide with iron impurities, SiO2)
Category
Browse mineral (man made glass, not natural) specimens identified by the Rock Identifier community.
Amethyst
Amethyst (Silicon Dioxide with iron impurities, SiO2)
Amethyst
SiO2 (Silicon Dioxide) - Purple variety of Crystalline Quartz
Sandstone
Arenite (SiO2 based clastic rock)
Yellow quartz, possibly citrine
Quartz (SiO₂), yellow variety likely citrine; may also be iron-stained quartz
Tumbled Amethyst and Smoky Quartz
Silicon Dioxide (SiO2) with impurities
Smoky Quartz
SiO2 (Silicon Dioxide)
Citrine
Quartz (SiO₂)
Sandstone (Ferruginous)
Arenite with Iron Oxide cement (SiO2 + Fe2O3)
Amethyst
Silicon Dioxide (SiO2) with iron impurities
Granite Pebble
Granite; primarily composed of Quartz (SiO2), Feldspar (KAlSi3O8), and Mica
Diorite (River Pebble)
Intermediate Phaneritic Igneous Rock
Marble
Recrystallized Calcite (CaCO3)
Smoky Quartz
Silicon Dioxide (SiO2)
Prasiolite
Silicon Dioxide (SiO2)
Chert (Flint)
Chert (Microcrystalline or cryptocrystalline Quartz - SiO2)
Banded Agate (specifically Sardonyx or Carnelian Agate)
Silicon Dioxide (SiO2) - Chalcedony variety
Granite
Phaneritic Igneous Rock (composed mostly of Quartz, Feldspar, and Mica)
Blue Sapphire
Corundum (Al2O3 with Cr, Fe, and Ti trace elements)
Pearl (nacre)
Calcium Carbonate (mostly CaCO3 as Aragonite) and Conchiolin
Diamond
Native Carbon (C)
Obsidian
Volcanic Glass (Amorphous SiO2)
Chert (and associated river cobbles)
Silicon dioxide (SiO2)
Chert
Microcrystalline Quartz (SiO2)
Rough Corundum (likely Sapphire or Common Corundum)
Aluminum oxide (Al2O3)
Blue Chalcedony
Chalcedony (Silicon Dioxide, SiO2)
Nacre (Mother of Pearl)
Nacre (Biogenic Aragonite/Calcite composite, CaCO3)
Specular Hematite (Specularite)
Iron Oxide (Fe2O3)
Chert (and/or Flint)
Chert (Cryptocrystalline variety of Quartz, SiO2)
Chert / Flint
Microcrystalline Quartz (SiO2)
Strawberry Quartz (Hematoid Quartz)
Silicon Dioxide with Hematite inclusions (SiO2 + Fe2O3)
Clear Quartz
Quartz (Silicon Dioxide, SiO2)
Clear Quartz (Rock Crystal)
Quartz (Silicon Dioxide, SiO2)
Sandstone
Arenite (SiO2 based)
Smoky Quartz
Smoky Quartz (Silicon Dioxide - SiO2)
Rounded pebble, likely quartz-rich sandstone or chert
Indeterminate lithic clast; possibly quartz arenite or microcrystalline quartz (SiO₂)
Hag Stone
Porous sedimentary rock (typically Flint, Chert, or Sandstone) with naturally occurring holes
Unknown Tumbled Stone
Unknown (Too Blurry)
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Dragon Vein Agate (Dyed)
SiO2
Diamond
C (Carbon)
Diamond
Natural Carbon (C)
Diamond
Diamond (Native Carbon, C)