Tumbled Gabbro
Gabbro (Mafic intrusive igneous rock)
igneous
Category
Man Made (Synthetic Rock)
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Amethyst (Tumbled)
Silicon Dioxide (SiO2) with Fe3+ impurities
mineral
Chert (Flint)
Microcrystalline Quartz (SiO2)
sedimentary
Sandstone (Red/Brown Variety)
Arenite (composed primarily of SiO2 with Fe2O3 iron oxide inclusions)
sedimentary
Coral Rock (Coquina)
Biogenic Limestone (Calcium Carbonate - CaCO3)
sedimentary
Diorite
Diorite (Intermediate intrusive igneous rock)
igneous
Sandstone (Pebble)
Sandstone (arenite, arkose, wacke depending on composition)
sedimentary
Diamond (in Jewelry Setting)
Carbon (C)
gemstone
Diamond in Kimberlite
Diamond (C in Kimberlite Matrix)
igneous
Dyed Blue Agate Slice
Silicon Dioxide (SiO2)
mineral
Hoodoo (Limestone / Siltstone Formation)
Claron Formation (Sedimentary Rock - Limestone, Mudstone, Dolomite)
sedimentary
Orange cabochon gemstone, likely amber or amber-like resin
Natural amber: fossilized plant resin (organic mineraloid), commonly succinite; exact identification requires testing
gemstone
Ruby (Pink to Red Corundum)
Al2O3 (Corundum with Chromium impurities)
mineral
Ruby
Corundum (Al2O3 with Chromium traces)
mineral
Blue Sapphire
Corundum (Al2O3)
mineral
Tumbled Clear Quartz and Citrine Points
Silicon Dioxide (SiO2)
mineral
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)
gemstone
Chert (Jasper / Quartz pebble)
Microcrystalline Quartz (SiO2)
sedimentary
Ruby (Corundum)
Corundum (Aluminum Oxide with Chromium), Al2O3:Cr
mineral
Coal (Anthracite/Bituminous)
Carbo fossilium (primarily Carbon)
sedimentary
Blue Sapphire
Corundum (Al2O3 with trace Titanium and Iron)
mineral
Petoskey Stone / Rugose Coral Fossil
Hexagonaria percarinata
fossil
Granite
Phaneritic plutonic rock (SiO2 typically >69%)
igneous
Smoky Quartz
Silicon Dioxide (SiO2) with aluminum impurities
mineral
Cardstock (Paper)
Cellulose (C6H10O5)n
sedimentary (man-made)
Blue Slag Glass
Amorphous Silica (Byproduct of smelting)
Antropogenic (Man-made)
Slag Glass (Cullet)
Amorphous Silicon Dioxide (SiO2) with metal oxide colorants
Anthropogenic (Man-made)
Slag (Anthropogenic Glass/Iron byproduct)
Ferro-silicate Slag
Anthropogenic (Man-made)
Chert (Yellow Jasper/Flint)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (Jasper/Flint variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Yellow Sapphire (Raw)
Corundum (Al2O3)
mineral
Banded Black Onyx (Chalcedony)
Silicon Dioxide (SiO₂)
mineral
Chert (Chocolate or Brown Flint)
Chert (SiO2)
sedimentary
Chalk
Micrite (primarily Calcium Carbonate, CaCO3)
sedimentary
Ammolite
Biogenic gemstone (Aragonite, CaCO3)
mineral
Blue chalcedony cabochon (probable)
Chalcedony, cryptocrystalline quartz; silicon dioxide (SiO₂)
gemstone
Industrial Slag
Anthropogenic Vitreous Slag
igneous
Corundum
Corundum (Al2O3)
Mineral
Tumbled amethyst
Quartz, crystalline silicon dioxide (SiO₂), purple variety colored mainly by iron impurities and irradiation
gemstone
Emerald
Beryl (Be3Al2(SiO3)6) with Chromium/Vanadium impurities
gemstone
Garden Quartz (Lodalite)
Silicon Dioxide with various mineral inclusions (SiO2)
mineral
Chert with Limestone
Silicon Dioxide (SiO2) in Calcium Carbonate (CaCO3) Matrix
sedimentary