Common Opal with Host Rock
Opal (Hydrated silica, SiO2·nH2O)
Category
Browse mineraloid (man made origin) specimens identified by the Rock Identifier community.
Common Opal with Host Rock
Opal (Hydrated silica, SiO2·nH2O)
Precious Opal
Hydrated Silica (SiO2·nH2O)
Mahogany Obsidian
Obsidian (volcanic glass with hematite/magnetite inclusions)
Chert
Microcrystalline Quartz (SiO2)
Obsidian
Volcanic Glass (70% or more SiO2)
Pumice
Pumice (Vesicular volcanic glass)
Pink Granite
Phaneritic Felsic Igneous Rock (Granite)
Obsidian
Volcanic Glass (comprised primarily of SiO2)
Black Obsidian
Volcanic Glass (predominantly SiO2, Silicon Dioxide)
Mahogany Obsidian
Volcanic glass (SiO2 + Fe2O3)
Chert (Jasper Variant likely)
Silicon Dioxide (SiO2)
Sandstone Concretion
Sedimentary concretion
Blue Lace Agate
Chalcedony (SiO2) with trace inclusions
White Quartz Pebble
Silicon Dioxide (SiO2)
Diamond
Native Carbon (C)
Turquoise
Turquoise (Hydrated phosphate of copper and aluminium) - CuAl6(PO4)4(OH)8·4H2O
Quartz (Clear Quartz/Rock Crystal)
Silicon Dioxide (SiO2)
Quartz
Silicon Dioxide (SiO2)
Quartz (Smoky Quartz variant)
Silicon Dioxide (SiO2)
Coquina
Bioclastic Limestone
Granodiorite Pebble
Granodiorite
Diamond
Diamond (pure Carbon, C)
Quartz (Milky or Smoky)
Silicon Dioxide (SiO2)
Clear Quartz
Silicon Dioxide (SiO2)
Coquina
Bioclastic Limestone (composed primarily of CaCO3)
Obsidian
Volcanic glass (SiO2 - Silicon Dioxide)
Blue Sapphire
Corundum (Al2O3) with traces of Iron and Titanium
Basalt
Mafic Igneous Rock (composed primarily of pyroxene and calcium-rich plagioclase)
Emerald
Beryl (Be3Al2(SiO3)6) with Chromium/Vanadium impurities
Engineered Quartz Stone
Agglomerated Quartz (SiO2 + Polymer Resin)
Limonite (Yellow Ochre)
Limonite (an amorphous mixture of hydrated iron oxides, primarily FeO(OH)·nH2O)
Sunstone (Aventurine Feldspar)
(Ca,Na)((Al,Si)2Si2O8) with inclusions of Cu or Fe2O3
Sunstone
(Ca,Na)((Al,Si)2Si2O8) - Plagioclase Feldspar
Limonite with Quartz (Gossan)
Hydrated iron(III) oxide-hydroxide mixture (FeO(OH)·nH2O) with Silicon Dioxide (SiO2)
White Opal (Common)
Hydrated Silica (SiO2·nH2O)
Petrified Wood
Silicified Wood (SiO2)
Chert (variations include Flint)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Druzy Quartz (on Geode Fragment)
Silicon Dioxide (SiO2)
Fossilized Coral (Coquina/Limestone)
Cnidaria Anthozoa (Fossilized)
Quartz Pebble
Silicon Dioxide (SiO2)
Quartz (River Pebble)
Silicon Dioxide (SiO2)
Diamond
Native Carbon (C)