Basalt (Polished pebble)
Basalt (Aphanitic mafic volcanic rock)
Category
Browse man made rock like material specimens identified by the Rock Identifier community.
Basalt (Polished pebble)
Basalt (Aphanitic mafic volcanic rock)
Sandstone (Micaceous Sandstone)
Arenite (SiO2 with KAl2(AlSi3O10)(OH)2 inclusions)
Amethyst
Silicon Dioxide (SiO2) with iron impurities
Quartz / Common Opal
Silicon Dioxide (SiO2)
Sandstone
Arenite (primarily SiO2)
Chert / Chalcedony (likely carnelian or flint variety)
Silicon Dioxide (SiO2)
Shale (possibly)
Shale (fine-grained clastic sedimentary rock)
Chert (Flint variety)
Chert (Cryptocrystalline Quartz, SiO2)
Banded Calcite (Mexican Onyx)
Calcium Carbonate (CaCO3)
Stichtite in Serpentine (Atlantisite)
Mg6Cr2CO3(OH)16·4H2O (Stichtite) within Mg3Si2O5(OH)4 (Serpentine)
Chert (Nodular Chert)
Microcrystalline or Cryptocrystalline Silicon Dioxide (SiO2)
Chert
Microcrystalline Quartz (SiO2)
Chert (Jasper/Flint variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Sandstone
Arenite (SiO2 based)
Turquoise
Hydrated copper and aluminum phosphate (CuAl6(PO4)4(OH)8·4H2O)
Picture Jasper
Silicon Dioxide (SiO2) with mineral inclusions
Gneiss
Gneissic Metamorphic Rock
Amazonite
Amazonite (KAlSi3O8, a triclinic variety of Potassium Feldspar)
Zebra Jasper
Silicon Dioxide (SiO2) with impurities; typically a form of Chalcedony/Microcrystalline Quartz
Red Sandstone
Arenite (primarily Quartz with Iron Oxide coating)
Biotite (Black Mica)
Biotite [K(Mg,Fe)3(AlSi3O10)(F,OH)2]
Amethyst Geode (Thunderegg)
Silicon Dioxide (SiO2) - Quartz Variety: Amethyst
Agate (or Banded Agate)
Agate (a variety of Chalcedony, which is a cryptocrystalline form of Quartz); Chemical Formula: SiO₂ (Silicon Dioxide)
Basalt
Basalt (Aphanitic Mafic Igneous Rock)
Greenstone / Diorite
Intermediate plutonic igneous rock
Basalt
Basalt
Sapphire (likely blue synthetic sapphire or blue glass in a ring)
Corundum (Al₂O₃), specifically the blue variety due to trace amounts of iron and titanium impurities. If synthetic, it would still be Al₂O₃.
Greenstone
Protolith of basalt, diabase, or gabbro; often contains minerals like chlorite, actinolite, and epidote
Milky Quartz Pebble (Iron-stained)
Silicon Dioxide (SiO2)
Olivine (Peridot)
Magnesium Iron Silicate (Mg,Fe)2SiO4
Muscovite Mica (in Quartz matrix)
Potassium aluminum silicate hydroxide fluoride (KAl2(AlSi3O10)(F,OH)2)
Blue Lace Agate
Silicon Dioxide (SiO₂), a variety of Chalcedony
River Cobble (likely Basalt)
Mafic Igneous Rock (Aphanitic)
Shale
Shale (clastic sedimentary rock)
Geode (Quartz)
Silicon Dioxide (SiO2)
Quartzite
Quartzite (SiO2)
Sandstone
Arenite (composed primarily of SiO2)
Kimberlite with Diamond
Kimberlite (Porphyritic Peridotite)
Petrified Wood
Silicified Wood (SiO2)
Rough Diamond
Native Carbon (C)
Nuummite
Nuummite (complex silicate composed of Anthophyllite and Gedrite, (Mg,Fe)7Si8O22(OH)2)
Diamond (Green tinted)
Carbon (C) with trace impurities or lattice defects