Rough Diamond
Native Carbon (C)
Category
Browse mineral (silicate replaced organic material) specimens identified by the Rock Identifier community.
Rough Diamond
Native Carbon (C)
Carnelian Agate
Carnelian (Silicon Dioxide - SiO2 with Iron Oxide impurities)
Diamond (Green tinted)
Carbon (C) with trace impurities or lattice defects
Diamond
Carbon (C)
Marble
Recrystallized Calcite (CaCO3)
Sandstone (Flagstone)
Arenite (composed primarily of SiO2)
Metal Alloy (Likely Pewter or Sterling Silver)
Not a natural geological specimen; composed of refined metals. If pewter, it's a tin-based alloy. If sterling silver, it's 92.5% silver and 7.5% other metals (usually copper).
Peridot (likely, based on color and appearance)
Olivine group mineral, specifically (Mg,Fe)2SiO4 (Forsterite-Fayalite solid solution series)
Sandstone (Water-worn)
Arenite
Spiny Oyster Shell
Spondylus (Calcium Carbonate, CaCO3)
Laterite
Laterite (no specific mineral formula as it's a rock type)
Yellow Quartz (Citrine Quartz Pebble)
Silicon Dioxide (SiO2)
Schist
Mica Schist
Emerald
Beryl (Be₃Al₂Si₆O₁₈), specifically the green variety colored by trace amounts of chromium or vanadium.
Herkimer Diamond
Quartz (SiO2)
Siltstone with Weathering Rind
Siltstone (composed of microscopic quartz and clay minerals)
Shale
Clastic sedimentary rock (primarily clay and silt minerals)
Quartz
Silicon Dioxide (SiO₂)
Sandstone (Quartzose Sandstone)
Clastic sedimentary rock (primarily SiO2)
Chert (Flint variety)
Chert (Cryptocrystalline variety of Quartz, SiO2)
Sandstone
Arenite (primarily SiO2)
Clear Quartz
Quartz (Silicon Dioxide, SiO2)
Sandstone (Quartzose Sandstone)
Arenite (primarily SiO2 with minor Fe2O3)
Sandstone (Quartzose)
Arenite (Formula: SiO2 primary, with various cements)
Granodiorite
Granodiorite (containing Plagioclase, Quartz, and Biotite)
Rose Quartz
Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese
Quartz
SiO₂ (Silicon Dioxide)
Schist
Mica Schist (primarily consisting of muscovite, biotite, and quartz)
Iron Slag
Iron Slag (Industrial Vitreous Material)
Blue Goldstone
Aventurine Glass (SiO2 with Co and metallic inclusions)
Fossilized Gastropod (Snail)
Class Gastropoda (internal mold or 'steinkern')
Jasper (specifically Fancy or Polychrome Jasper)
Silicon Dioxide (SiO2) - Chalcedony
Labradorite
Labradorite ((Ca, Na)(Al, Si)4O8)
Milky or Iron-Stained Quartz
Quartz (Silicon Dioxide, SiO2)
Quartz (Milky or White Quartz)
Silicon Dioxide (SiO2)
Mica Schist
Mica Schist (primarily Muscovite and Biotite KAl2(AlSi3O10)(OH)2)
Sandstone (with possibly iron oxides and other minerals)
Sandstone
Yellow Jasper
Jasper (Silicon Dioxide, SiO2)
Flowerstone
Porphyritic Basalt or Porphyritic Andesite
Sandstone (Red/Brown Variety)
Arenite (composed primarily of SiO2 with Fe2O3 iron oxide inclusions)
Granite (Alkali-feldspar Granite)
Felsic Plutonic Rock (Primary minerals: Quartz SiO2, Orthoclase KAlSi3O8, Plagioclase (Na,Ca)AlSi3O8)
Sandstone
Arenite (composed primarily of SiO2)