Basalt
Mafic Igneous Rock (composed primarily of pyroxene and calcium-rich plagioclase)
Category
Browse mineraloid (man made origin) specimens identified by the Rock Identifier community.
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)
Limonite with Quartz (Gossan)
Hydrated iron(III) oxide-hydroxide mixture (FeO(OH)·nH2O) with Silicon Dioxide (SiO2)
White Opal (Common)
Hydrated Silica (SiO2·nH2O)
Sunstone (Aventurine Feldspar)
(Ca,Na)((Al,Si)2Si2O8) with inclusions of Cu or Fe2O3
Sunstone
(Ca,Na)((Al,Si)2Si2O8) - Plagioclase Feldspar
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)
Peridot
Olivine ((Mg,Fe)2SiO4)
Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
Blue Sapphire (Ceylon)
Corundum (Al2O3) with traces of Iron and Titanium
Gypsum (Satin Spar / Alabaster variety)
Calcium Sulfate Dihydrate (CaSO4·2H2O)
Granite
Plutonic Igneous Rock (composed typically of SiO2, Al2O3, K2O, Na2O, CaO)
US Penny
Cuprum (Copper: Cu) and Zincum (Zinc: Zn) Alloy
Limonite and Goethite (Ironstone)
Hydrous Iron Oxide Mixture (FeO(OH)·nH2O)
Granite
Phaneritic Igneous Rock (composed primarily of Quartz, Alkali Feldspar, and Plagioclase)
Granodiorite
Phaneritic Plutonic Intermediate-Felsic Rock
Ferruginous Sandstone with Quartz Inclusions
Clastic Sedimentary Rock (Iron-rich Sandstone)
Sapphire
Corundum (Al2O3)
Limonite (Iron Ore)
Limonite (an FeO(OH)·nH2O mineraloid, not a true mineral due to variable composition)
Sapphire
Corundum (Al2O3)
Ruby
Corundum (Al2O3:Cr)
Quartz Geode (Cracked)
Silicon Dioxide (SiO2)
Quartzite
Quartzite (SiO2)
Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
Quartz (Milky/Rose variety)
Silicon Dioxide (SiO2)
Quartz (River Pebble)
Silicon Dioxide (SiO2)
Pink Sapphire
Corundum (Al2O3 with trace Chromium and Iron)
Granite
Granite (Phaneritic igneous rock)
Chalk
Micrite (primarily Calcium Carbonate or CaCO3)
Diabase (Greenstone)
Diabase (also known as Dolerite)
Chert (specifically Tan/Gray Chert)
Microcrystalline quartz (SiO2)
Chert (varietal: Flint/Jasper)
Silicon Dioxide (SiO2)
Obsidian
Volcanic Glass (Primary composition: SiO2 - Silicon Dioxide)