Shale (sub-type: Carbonaceous Shale)
Lutaceous Sedimentary Rock
sedimentary
Category
Organic Gemstone (Fossilized Resin)
Browse organic gemstone (fossilized resin) specimens identified by the Rock Identifier community.
Citrine
Silicon Dioxide (SiO2)
mineral
Almandine Garnet in Matrix
Almandine, Fe3Al2(SiO4)3
metamorphic
Septarian Nodule or Mud Crack Fossil
Septarian Nodule (Concretion)
sedimentary
Chert (variations include Flint or Jasper)
Silicon Dioxide (SiO2)
sedimentary
Jasper
Agate/Jasper (Microcrystalline Quartz, SiO2)
sedimentary
Jasper (Mookaite variety likely)
Silicon Dioxide (SiO2) with iron oxide inclusions
sedimentary
Septarian Nodule (Dragon Stone)
Septarian Concretion (CaCO3 with Siderite and Calcite)
sedimentary
Banded Chert (Ironstone/Jasper)
Cryptocrystalline Quartz (SiO2) with Iron Oxides
sedimentary
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Septarian Nodule (Dragon Stone)
Septarian Geode (CaCO3 + Mg + Fe)
sedimentary
Chert (Yellow Jasper variant)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (Brecciated or Veined)
Silicon Dioxide (SiO2)
sedimentary
Chert (Iron-Stained)
Microcrystalline or cryptocrystalline Quartz (SiO2)
sedimentary
Amethyst
Silicon dioxide (SiO2)
mineral
Rhodochrosite (Beads) and Citrine (Pendant)
Rhodochrosite (MnCO3) and Quartz variety Citrine (SiO2)
mineral
Moss Agate
Chalcedony (Silicon Dioxide with inclusions) - SiO2
mineral
Cat's Eye Moonstone (Feldspar)
Orthoclase (KAlSi3O8) with Albite (NaAlSi3O8) inclusions
mineral
Moonstone
Orthoclase (Potassium Aluminum Silicate), Formula: (K,Na)AlSi3O8
mineral
Olivine (Peridotite)
Magnesium iron silicate (Mg, Fe)2SiO4
igneous
Peridot (Olivine)
Magnesium Iron Silicate (Mg,Fe)2SiO4
mineral
Cubic Zirconia (CZ)
Zirconium dioxide (ZrO2)
mineral
Shale with Vein Infillings
Shale (a fine-grained clastic sedimentary rock). The veins could be Calcite (CaCO3), Quartz (SiO2), or other minerals.
Sedimentary Rock
Petrified Wood
Silicified Wood (primarily SiO2)
sedimentary
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Petrified Wood
Silicified Wood (primarily SiO2 - Silicon Dioxide)
mineral
Chert (often called Flint when dark)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Chert (Green variety)
Microcrystalline or cryptocrystalline Quartz (SiO2)
sedimentary
Petrified Wood (Agatized/Silicified Wood)
Silicified Wood / Chalcedony (SiO2)
sedimentary
Chert (Iron-stained)
Microcrystalline or cryptocrystalline Quartz (SiO2)
sedimentary
Chert (Flint)
Chert (Cryptocrystalline variety of Quartz, SiO2)
sedimentary
Pearl
Aragonite (CaCO3) with Conchiolin
mineral
Emerald in Host Rock
Beryl (Be3Al2Si6O18) containing Chromium and/or Vanadium
mineral
Jasper (Petrified Wood variant)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
sedimentary
Ironstone Concretion (Limonite/Hematite Nodules)
Ironstone (principally Limonite FeO(OH)·nH2O or Hematite Fe2O3 mixed with silica/clay)
sedimentary
Quartz Geode
Silicon Dioxide (SiO2) within a secondary sedimentary structure
sedimentary
Grey and White Chert (Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Petrified Wood
Silicified Wood (SiO2)
metamorphic
Chert (Flint Pebbles)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Chert (Quartz Variety)
Microcrystalline Silica (SiO2)
sedimentary
Rhodonite
Manganese silicate (Mn,Fe,Mg,Ca)SiO3
mineral
Moonstone (Feldspar)
Orthoclase feldspar, (K,Na)AlSi3O8
mineral