Chert / Flint
Microcrystalline Quartz (SiO2)
Category
Browse antropogenic (man made material) specimens identified by the Rock Identifier community.
Chert / Flint
Microcrystalline Quartz (SiO2)
Quartzite
Metamorphic Quartzite (SiO2)
Flint
SiO2 (Cryptocrystalline Quartz)
Brecciated Jasper
Brecciated Jasper (Microcrystalline Quartz / SiO2)
Green Aventurine
Silicon Dioxide (SiO2+KAl2(AlSi3O10)(OH)2)
Granite
Granite (composed primarily of Quartz, Feldspar, and Mica)
Gabbro
Gabbro (Mg, Fe)2Si2O6 / (Ca, Na)(Al, Si)4O8
Chert (with Quartz)
Microcrystalline Quartz (SiO2)
Quartzite
Metamorphic Quartzite
Green Quartzite
Metamorphic Quartz Sandstone (SiO2)
Red Quartzite
Quartzite (Metamorphosed Quartz Arenite)
Quartzite
Metamorphic Quartz Rock (SiO2)
Natural Pearl
Calcium carbonate (primarily Aragonite and Conchiolin), CaCO3
Turquoise
Hydrated phosphate of copper and aluminium: CuAl6(PO4)4(OH)8·4H2O
Tumbled blue-green stone, likely chrysocolla or dyed chalcedony
Probable chrysocolla (hydrated copper aluminosilicate; variable composition), though appearance could also represent dyed chalcedony
Petoskey Stone / Rugose Coral Fossil
Hexagonaria percarinata
Likely blue glass or synthetic gemstone jewelry
Uncertain; possibly synthetic spinel, cubic zirconia, or blue glass
Fossil Coral
Scleractinia (Stony Coral) fossil
Bog Iron / Limonite Concretion
Goethite/Limonite mixture (FeO(OH)·nH2O)
Polished white chalcedony or milky quartz pebble
Chalcedony, microcrystalline quartz (SiO₂), possibly with iron-oxide staining or a minor mineral inclusion
Quartzite
Metamorphic Rock (Mainly SiO2)
Mixed Gemstone Beaded Jewelry
Various minerals (e.g., Quartz varieties like Rose Quartz, Amethyst; Peridot; Garnet; etc.)
Sandstone
Arenite
Sandstone
Arenite (mostly SiO2)
Granite
Granite (Plutonic Igneous Rock)
Granite
Granite (phaneritic intrusive igneous rock consisting of quartz, feldspar, and mica)
Granite
Granite (Felsic Plutonic Rock)
Granite
Granite (Silicic Intrusive Igneous Rock)
Red Swirl Beads (Likely Resin or Glass, simulating Red Jasper or Agate)
N/A (for the beads as pictured); Red Jasper: SiO2 (Chert variety); Red Agate: SiO2 (Chalcedony variety)
Diamond
Carbon (C)
Chert
Microcrystalline Quartz (SiO2)
Banded Jasper / Chert Beach Pebble
Microcrystalline Quartz (SiO2)
Chert
Microcrystalline Quartz (SiO2)
Chert / Flint
Silicon Dioxide (Microcrystalline Quartz, SiO2)
Flint / Chert
Microcrystalline quartz (SiO2)
Brecciated Jasper
Silicon Dioxide (SiO2) with iron oxide inclusions
Smoky Quartz
Smoky Quartz (SiO2)
Pearl
Organic gemstone (Calcium carbonate - CaCO3)
Pearl
Calcium carbonate (CaCO3) - mainly Aragonite with Conchiolin
Diamond (in a jewelry setting)
Cubic Carbon (C)
Granodiorite
Granodiorite (phaneritic intrusive igneous rock)
Obsidian
Volcanic Glass (SiO2)