Agate (Slab)
Agate (Cryptocrystalline variety of Quartz, SiO2)
Category
Browse industrial byproduct (often mistaken for obsidian or mineral) specimens identified by the Rock Identifier community.
Agate (Slab)
Agate (Cryptocrystalline variety of Quartz, SiO2)
Garnet (Almandine)
Almandine (Fe3Al2(SiO4)3)
Banded Flint (Polished Stripe Flint)
Silicon Dioxide (SiO2) - variety of Chert
White Quartz Pebble
Silicon Dioxide (SiO2)
Milky Quartz with Iron Staining
Silicon Dioxide (SiO2)
Banded Agate (Lace Agate)
Agate (Variety of Cryptocrystalline Quartz), SiO2
White Agate (Chalcedony)
Silicon Dioxide (SiO2)
Quartzite
Quartzite (Primary mineral: SiO2)
Blue Sapphire
Corundum (Al2O3 - Aluminum Oxide)
Agate
Banded Chalcedony (SiO2 - Silicon Dioxide)
Almandine Garnet & Tumbled Citrine Quartz
Fe3Al2(SiO4)3 (Garnet) and SiO2 (Quartz)
Blue Zircon
Zirconium Silicate (ZrSiO4)
Wishing Stone with Quartz Vein
Hydrothermal Quartz Vein in Metasedimentary Matrix (primarily SiO2)
Goldstone
N/A (Synthetic Glass with Copper Inclusions)
Honey Calcite (Yellow Calcite)
Calcium Carbonate (CaCO3)
Howlite
Howlite (Ca2B5SiO9(OH)5)
Citrine
Quartz (SiO₂)
Bouncy Ball (Synthetic Rubber Polymer)
Polybutadiene / Ethylene Vinyl Acetate (EVA)
Banded Chert
Microcrystalline Quartz (SiO2)
Chalcedony (Agate)
Cryptocrystalline Quartz (SiO2)
Granitic Pegmatite
Granite Pegmatite (principally KAlSi3O8, SiO2, and KAl2(AlSi3O10)(OH)2)
Greenschist (Chlorite Schist)
Greenschist (Metamorphic rock dominated by chlorite, actinolite, and epidote)
Diamond
Diamond (Pure Carbon - C)
Ruby
Corundum (Al2O3 with Chromium)
Druzy Quartz on Matrix
Silicon Dioxide (SiO2)
Chert (Cherty Limestone / Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Orange Calcite
Calcium Carbonate (CaCO3)
Chert or Flint (polished/water-worn)
Chert (a microcrystalline or cryptocrystalline variety of quartz, SiO2). Flint is a specific variety of chert.
Garnet Schist
Almandine Garnet in Mica Schist (Fe3Al2(SiO4)3)
Gold Nugget
Native Gold (Au)
Olivine (Peridot when gem-quality)
Magnesium Iron Silicate, (Mg,Fe)2SiO4
Ferruginous Sandstone (Gerrit)
Arenite with Iron Oxide cementation
Rose Quartz
Rose Quartz (SiO₂)
Sodalite
Sodalite (Na8Al6Si6O24Cl2)
Quartzite
Quartzite (Primary mineral: SiO2)
Stilbite
Stilbite-Ca (NaCa4(Si27Al9)O72·28H2O)
Quartzite (River Cobble)
Quartzite (dominant mineral: Quatrz, SiO2)
Black Star Diopside
Diopside (CaMgSi2O6) with Magnetite inclusions
Quartz Druzy on Matrix (likely Agate or Jasper)
Silicon Dioxide (SiO2) with various mineral inclusions
Ruby (Corundum)
Corundum (Aluminum Oxide) with chromium trace elements, Al2O3
Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
Quartz Pebble
Silicon Dioxide (SiO2)