Chert (often called Flint when dark)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Category
Browse industrial byproduct (anthropogenic material) specimens identified by the Rock Identifier community.
Chert (often called Flint when dark)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Tree Agate (or Moss Agate)
Dendritic Agate (Silicon Dioxide - SiO2)
Blue Topaz (facetted in jewelry)
Aluminum silicate fluoride hydroxide (Al2SiO4(F,OH)2)
Basalt
Basalt (Mafic volcanic rock)
Bauxite
Bauxite (Al(OH)3 mixed with Fe2O3 and clay minerals)
Quartzite
Quartzite (primarily SiO2)
Quartzite
Quartzite (SiO2)
Bauxite
Bauxite (Al(OH)3, AlO(OH))
Nephrite Jade
Ca2(Mg, Fe)5Si8O22(OH)2
Basalt (Road Aggregate / Crushed Stone)
Aphanitic Mafic Igneous Rock
Andesite
Intermediate Volcanic Rock (Andesite)
Basalt
Extrusive Igneous Basalt (contains Plagioclase Feldspar and Pyroxene)
Opalite
Man-made opalescent glass (SiO2 + metal oxides)
Blue Agate (Tumbled and Dyed)
Silicon Dioxide (SiO2) with likely organic dyes
Petrified Wood
Silicified Wood (primarily Chalcedony/Quartz, SiO2)
Jasper
Jasper (Silicon Dioxide) - SiO2
Zebra Rock / Zebra Marble
Banded Limestone-Marble Transition
Petrified Wood
Silicified wood (Quartz, SiO2)
Petrified Wood
Silicified Wood (primarily SiO2)
Red Jasper
Silicon Dioxide (SiO2) with Hematite inclusions
Sandstone
Arenicola (comprising mostly Quartz, SiO2)
Petrified Wood
Silicified Wood (primarily SiO₂)
Petrified Wood
Silicified Wood (SiO2)
Chert (often referred to as 'Jasper' when red)
Chert (microcrystalline quartz, SiO₂)
Corundum (Sapphire)
Corundum (Al2O3)
Epidote
{Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH)
Olivine (Peridot)
Magnesium Iron Silicate (Mg,Fe)2SiO4
Quartz (Small Fragment)
Silicon Dioxide (SiO2)
Garnet Schist
Almandine Garnet (Fe3Al2(SiO4)3) in Mica Schist
Basalt with Sulfide/Pyrite inclusion
Aphanitic Mafic Igneous Rock (likely Basalt) with Pyrite (FeS2)
Pegmatite
Granitic Pegmatite
Rough Gemstone Grains (Mixed Sapphires and Quartz)
Corundum (Al2O3) and Quartz (SiO2)
Schist
Mica Schist (Quartz-Muscovite-Biotite Schist)
Emerald
Beryl (Be3Al2(SiO3)6) with Chromium/Vanadium impurities
Milky Quartz Pebble with Chert
Silicon Dioxide (SiO2)
Aquamarine
Beryl (Be3Al2Si6O18)
Native Copper
Native Copper (Cu)
Fluorite (Green)
Fluorite (Calcium Fluoride, CaF2)
Quartzite (Water-worn Pebble)
Metamorphosed Quartz Sandstone (SiO2)
Quartz (Citrine or Iron-stained Quartz)
Silicon Dioxide (SiO2)
Quartz (Iron-stained)
Silicon Dioxide (SiO2)
Rose Quartz Beads
SiO2 (Silicon Dioxide with trace inclusions of Ti, Fe, or Mn)