Unakite
Epidotized Granite (SiO2, KAlSi3O8, Ca2(Al, Fe)3(SiO4)3(OH))
Category
Browse anthropogenic material (man made rock) specimens identified by the Rock Identifier community.
Unakite
Epidotized Granite (SiO2, KAlSi3O8, Ca2(Al, Fe)3(SiO4)3(OH))
Diorite
Intrusive Igneous Rock (Intermediate Composition)
Granite
Granite (Felsic Intrusive)
River Rock (Quartzite/Chert conglomerate)
Quartzite (SiO2)
Crushed Granite Gravel
Granite (composed primarily of Quartz, Alkali Feldspar, and Plagioclase Feldspar)
Chert (Jasper/Flint variety)
Microcrystalline Quartz (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Chert (varieties include Flint and Jasper)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Obsidian
Obsidian (Volcanic Glass; SiO2 content > 70%)
Conglomerate
Conglomerate (clastic sedimentary rock)
Dendritic Agate (Tree Agate)
Chalcedony (Silicon Dioxide, SiO2) with Manganese or Iron Oxide inclusions
Sandstone (Water-worn)
Arenite
Basalt
Basalt (Mafic volcanic rock)
Note regarding image quality
Chert (often called Flint or Jasper depending on color)
Chert (SiO2 - Microcrystalline or Cryptocrystalline Quartz)
Serpentine (Serpentinite)
Serpentinite (complex silicate group including lizardite, chrysotile, and antigorite)
Sandstone
Sandstone (lithified quartz arenite, arkose, graywacke, etc. depending on composition)
Mookaite Jasper
Silicified Radiolarite (SiO2)
Gneiss
Gneiss (quartz-feldspar-biotite gneiss)
Diorite
Diorite (intermediate intrusive igneous rock)
Diorite
Diorite (Intermediate intrusive igneous rock)
Garnet
Almandine (Fe3Al2(SiO4)3)
Olivine/Peridot
Magnesium Iron Silicate (Mg,Fe)2SiO4
Aventurine
Aventurine Quartz (SiO2 with inclusions)
Dyed Agate
Silicon Dioxide (SiO2) - variety Chalcedony
Chert (Flint)
Microcrystalline Quartz (SiO2)
Pink Granite
Granite (Felsic intrusive igneous rock)
Shale or Mudstone (Based on appearance)
Shale (fine-grained, laminated fissile sedimentary rock) / Mudstone (fine-grained, non-fissile sedimentary rock)
Chert (and Jasper blend)
Chert (Microcrystalline Quartz, SiO2)
Quartz Pebble
Silicon Dioxide (SiO2)
Granite
Granitic intrusive igneous rock
Botryoidal Malachite
Malachite - Cu2CO3(OH)2
Quartz
Quartz (SiO₂)
Red Sandstone
Clastic sedimentary rock (primarily SiO2 with Fe2O3)
Obsidian
Obsidian (principally SiO2)
Fossil Coral
Scleractinia (Anthos), primarily Calcium Carbonate (CaCO3)
Chert (Agatized/Banded)
Chert (Microcrystalline Silicon Dioxide, SiO2)
Petrified Wood (Silicified Wood)
Silicified Wood / Silicon Dioxide (SiO2)
Diorite (with Iron Staining)
Phaneritic Intermediate Igneous Rock
Sunstone
Oligoclase or Andesine (Plagioclase Feldspar) - (Ca, Na)((Al, Si)2Si2O8)
Chert (Iron-rich or Jasperoid)
Cryptocrystalline Quartz (SiO2)
Chert / Jasper / Agate (Chalcedony Group)
Microcrystalline Quartz (SiO2)