Granite Pebble
Granite (Phaneritic intrusive igneous rock comprising Quartz, Feldspar, and Mica)
Category
Browse anthropogenic (man made material) specimens identified by the Rock Identifier community.
Granite Pebble
Granite (Phaneritic intrusive igneous rock comprising Quartz, Feldspar, and Mica)
Blue-beaded gemstone jewelry, likely lapis lazuli or dyed blue agate
Uncertain from the image; possible lazurite-bearing lapis lazuli (Na₃Ca(Si₃Al₃)O₁₂S) or blue chalcedony (SiO₂)
Slag (Industrial Glass)
Anthropogenic Vitreous Slag (Post-industrial byproduct)
Chert (Chocolate or Brown Flint)
Chert (SiO2)
Petrified Wood (Silicified Wood)
Silicified Paleoflora (mainly Quartz, SiO2)
Quartzite
Silica (SiO2) quartzite
Coral Rock (Coquina)
Biogenic Limestone (Calcium Carbonate - CaCO3)
Diamond
Carbon (C)
Aragonite Star Cluster
Aragonite (Calcium Carbonate, CaCO3)
Banded Calcite (often commercially sold as 'Mexican Onyx' or 'Honey Onyx')
Calcite (Calcium Carbonate, CaCO3)
Chert (variations include Flint/Novaculite)
Chert (formula: SiO2)
Chert (often called Flint for darker varieties)
Silicon Dioxide (SiO2) - Cryptocrystalline Quartz
Chert (and Jasper/Chalcedony mixture)
Microcrystalline Quartz (SiO2)
Chert (Flint)
Microcrystalline quartz (SiO2)
Granodiorite
Granodiorite
Tree Agate
Chalcedony (SiO2)
Coal (Anthracite / Bituminous)
Organic Sedimentary Rock (Carbon-based)
Chert (Nodule)
Chert (SiO2)
Petrified Wood
Silicified Wood (primarily SiO2)
Chert (and Flint)
Silicon Dioxide (SiO2)
Sandstone
Arenite
Basalt
Basalt
Ferro-Manganese Slag
Vitreous Silicate Slag
Diorite
Intermediate plutonic igneous rock
Diamond (in a jewelry setting)
Diamond (Carbon, C)
Diorite
Diorite
Chert Arrowhead
Cryptocrystalline microcrystalline Quartz (SiO2)
Polished blue-green glassy slag or coated mineral fragment
Most likely man-made colored glass/slag; exact composition cannot be determined visually
Goldstone
N/A (Synthetic Glass with Copper Inclusions)
Chert (Jasper/Flint variety)
Microcrystalline Quartz (SiO2)
Pearl
Pearl (Calcium Carbonate with organic conchiolin, CaCO3)
Granite
Phaneritic plutonic rock (SiO2 typically >69%)
Lapis lazuli and green-blue chalcedony jewelry
Lapis lazuli: lazurite-bearing metamorphic rock, chiefly lazurite (Na₃Ca(Al₃Si₃O₁₂)S) with calcite and pyrite; second stone: likely chrysoprase or green-blue chalcedony (microcrystalline quartz, SiO₂)
Banded Calcite (often sold as 'Mexican Onyx' or 'Green Onyx')
Calcite (Calcium Carbonate, CaCO3)
Diamond
Carbon (C)
Coquina
Biogenic Limestone (Calcite/Aragonite base, CaCO3)
Chert
Microcrystalline Quartz (SiO2)
Tektite
Impactite (Natural Silicate Glass)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Chert (Nodule/Pebble)
Chert (Silicon Dioxide, SiO2)
Chert (Jasper/Flint variant)
Silicon Dioxide (SiO2)
Marble
Recrystallized Calcite (CaCO3)