Mahogany Obsidian
Obsidian (Volcanic Glass) with Hematite/Magnetite inclusions
Category
Browse sedimentary (processed mineral product) specimens identified by the Rock Identifier community.
Mahogany Obsidian
Obsidian (Volcanic Glass) with Hematite/Magnetite inclusions
Opalite (Man-made Glass)
Fused glass (typically made of dolomite and metal opacifiers)
Sandstone
Arenite (primarily SiO2)
Sandstone (Ferruginous)
Arenite (primarily SiO2 with Fe2O3 staining)
Dragon Vein Agate
Silicon Dioxide (SiO2)
Sandstone
Quartz Sandstone (predominantly)
White Marble
Recrystallized Calcite (CaCO3)
Limonite (Ironstone)
Limonite (mixture of hydrated iron oxides, primarily Goethite α-FeO(OH))
Sandstone (likely River-tumbled Picture Sandstone)
Arenite (predominantly SiO2 with iron oxide impurities)
Milky Quartz
Quartz (Silicon Dioxide - SiO2)
Sandstone
Arenite (composed primarily of SiO2)
Precious Opal
Hydrated Silica (SiO2·nH2O)
Sandstone
Arenite (primarily SiO2)
Sandstone (River Rock)
Arenite (composed primarily of SiO2)
Septarian Nodule
Septarian Concretion (Calcium Carbonate/Aragonite/Calcite)
Greenstone
Greenschist (primarily composed of chlorite, actinolite, and epidote)
Sandstone (Water-worn Pebble)
Clastic Sedimentary Rock (primarily SiO2)
Gneiss
Gneiss (high-grade metamorphic rock)
Sandstone Concretion
Clastic Sedimentary Rock (primarily SiO2 with mineral cement)
Malaysian 50 Sen Coin
Coinage (specific alloy unknown without metallurgical analysis, but typically brass or bronze for this denomination and era)
Man-made Blank Ammunition (Brass)
CuZn (Cartridge Brass - roughly 70% Copper, 30% Zinc)
Sandstone (with potential mineral inclusions)
Clastic sedimentary rock (primarily Quartz, SiO2)
Lapis Lazuli
Lazurite-dominant rock, (Na,Ca)8(AlSiO4)6(SO4,S,Cl)2
Sandstone (Yellow/Siltstone variant)
Arenite (SiO2 primarily)
Blue Lace Agate
Silicon Dioxide (SiO₂)
Green Fluorite
Fluorite (Calcium Fluoride, CaF2)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Clear Quartz (Carved Merkaba)
Silicon Dioxide (SiO2)
Sandstone (Ferruginous)
Arenite with Iron Oxides
Sandstone
Arenite
Sedimentary Breccia
Breccia (Clastic Sedimentary Rock)
Fluorite
Calcium fluoride (CaF2)
Yellow Jasper
Chalcedony (Silicon Dioxide with Iron inclusions), SiO2
Turquoise (set in silver jewelry)
Turquoise - CuAl6(PO4)4(OH)8·4H2O (Hydrated copper and aluminum phosphate)
Turquoise
CuAl6(PO4)4(OH)8·4H2O
Pyrite
Iron Sulfide (FeS2)
Turquoise
Turquoise (Hydrated phosphate of copper and aluminium) CuAl6(PO4)4(OH)8·4H2O
Tree Agate
Silicon Dioxide (SiO2) with Chlorite inclusions
Calcite
Calcium Carbonate (CaCO3)
Pyrite
Iron Sulfide (FeS2)
Pyrite in Matrix (often with Chalcopyrite)
Iron Sulfide (FeS2) / Copper Iron Sulfide (CuFeS2)
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2 with iron oxide inclusions)