Blue Quartzite (Aventurine)
Silicon Dioxide (SiO2) with mineral inclusions
metamorphic
Category
Not A Rock (Man Made Origin)
Browse not a rock (man made origin) specimens identified by the Rock Identifier community.
Green Fluorite
Calcium Fluoride (CaF2)
mineral
Fluorite (specifically Rainbow Fluorite or Purple Fluorite)
Calcium Fluoride (CaF2)
mineral
Fluorite (Purple Octahedron)
Calcium Fluoride (CaF2)
Mineral
Amber
Succinite (with a generalized formula of C10H16O)
mineral
Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Quartz (Common Quartz Pebble)
Silicon Dioxide (SiO2)
mineral
Chert (Common Opal/Agate inclusion)
Microcrystalline Quartz (SiO2)
sedimentary
Amber
Succinite (Fossilized Tree Resin) - C10H16O
mineral
Granite
Phaneritic Igneous Rock (primarily Quartz, Feldspar, and Mica)
igneous
Marble
Marbles are primarily composed of calcite (calcium carbonate, CaCO3) or dolomite (calcium magnesium carbonate, CaMg(CO3)2).
Metamorphic Rock
Chalk
CaCO3 (primarily Calcium Carbonate), biogenic sedimentary rock
Sedimentary
Terrazzo (Synthetic Composite Rock)
Cementitious or Epoxy Resin-bound Aggregates
Man-made metamorphic-style composite
Ambergris
Ambergris (Coprolite-adjacent organic substance)
Organic (Geological interest)
Diamond (Princess Cut)
Carbon (C)
mineral
Diamond
Natural Carbon (C)
mineral
Popcorn
Zea mays everta (P. Wilson) (Botanical name for the corn variety)
Organic/Biogenic
Diamond
Native Carbon (C)
mineral
Corundum (Ruby variety)
Aluminium oxide (Al2O3)
mineral
Diamond (as set in a gold ring)
Carbon (C)
mineral
Pearl
Calcium Carbonate (CaCO3) in the form of orthorhombic Aragonite and Conchiolin
mineral
Rough Green Fluorite
Fluorite (Calcium Fluoride - CaF2)
mineral
Fluorite (Rainbow/Purple Fluorite)
Calcium Fluoride (CaF2)
mineral
Emerald
Beryl (Be3Al2Si6O18) with trace amounts of Chromium and/or Vanadium
mineral
Granite (weathered pebble)
Granite (plutonic igneous rock)
Igneous
Quartz
Silicon Dioxide (SiO₂)
Mineral
Gastly (Trick or Trade Halloween Series)
Cellulose-carbonaceous composite (Lignocellulose laminated with pigmentary polymers)
Mineral (Synthetic - Paper and Ink Polymorph)
Emerald
Beryl (Be3Al2(SiO3)6) with Chromium/Vanadium impurities
mineral
Jasper with Quartz Vein
Silicon Dioxide (SiO2) with impurities
sedimentary
Granite
Granite (a common rock type, not a single mineral with a formula. Composed primarily of quartz, feldspar, and mica/amphibole).
igneous
Chalcanthite (Likely Synthetic/Lab-Grown)
Hydrated copper(II) sulfate (CuSO4·5H2O)
mineral
Demantoid Garnet on Matrix
Demantoid (variety of Andradite Garnet) - Ca3(Fe3+)2(SiO4)3
mineral
Precious Opal
Hydrated Silica (SiO2·nH2O)
mineral
Green Aura Quartz
Silicon Dioxide (SiO2) bonded with metallic vapors (typically Gold, Chromium, or Titanium)
mineral
Diamond
Native Carbon (C)
mineral
Pumice
Pumicite (fine-grained pumice), Scoria (similar origin but denser and darker, usually basaltic)
Igneous
United States Quarter Dollar
Cupronickel Clad Alloy (75% Copper, 25% Nickel over a 100% Copper core)
Metal / Man-made mineral-like object
Amethyst and Citrine (Ametrine Mix)
Silicon Dioxide (SiO2) with Fe3+ impurities
mineral
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Rough Diamond
Native Carbon (C)
mineral
Corundum (Sapphire/Ruby in Matrix)
Corundum (Al2O3)
mineral
Diamond
Diamond (pure native carbon, C)
mineral