Chert (Commonly known as Flint)
Microcrystalline Quartz (SiO2)
Category
Browse organic gemstone (often associated with sedimentary sequences) specimens identified by the Rock Identifier community.
Chert (Commonly known as Flint)
Microcrystalline Quartz (SiO2)
Stromatolite (Fossiliferous Limestone)
Biogenic Limestone (Calcium Carbonate, CaCO3)
Chert (and its variety Flint)
Silicon Dioxide (SiO2) - Microcrystalline or cryptocrystalline Quartz
Likely chert or flint
Microcrystalline quartz (SiO₂), commonly called chert; exact identification requires testing
Lepidolite
K(Li,Al)3(Si,Al)4O10(F,OH)2
Chert (Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Clear Quartz (Faceted) or Cubic Zirconia / Glass imitation
SiO2 (if Quartz), ZrO2 (if Cubic Zirconia)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Chert (Black Chert/Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Biotite Schist
Biotite Schist (K(Mg,Fe)3AlSi3O10(OH,F)2)
Chert (River Pebble)
Silicon Dioxide (SiO2)
Chert (Flint)
Chert (Silicon Dioxide, SiO2)
Chert (Jasper/Flint variety)
Microcrystalline quartz (SiO2)
Shale
Fissile Clay-dominant Mudrock (SiO2, Al2O3, K2O, Na2O, CaO, MgO)
Petrified Wood
Silicified Wood (primarily SiO2)
Chalcedony (Carnelian/Agate)
Silicon Dioxide (SiO2)
Amber
Succinite (fossilized tree resin)
Glauconitic Sandstone
Glauconite-bearing Arenite (K,Na)(Fe,Al,Mg)2(Si,Al)4O10(OH)2
Quartz
Silicon Dioxide (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Chert (varietal: Jasper or Flint)
Silicon Dioxide (SiO2) - Cryptocrystalline Quartz
Chert (Red Jasper variant)
Microcrystalline Quartz (SiO2)
Chert (variant Flint)
Silicon Dioxide (SiO2)
Chert (Flint variety)
Chert (Microcrystalline or Cryptocrystalline Quartz), SiO2
Chert
Microcrystalline Quartz (SiO2)
Banded Chert
Microcrystalline Quartz (SiO2)
Ferruginous Sandstone Concretion (Ironstone Phosphorite)
Ferruginous Sandstone (variable Fe-oxide/hydroxide composition)
Unakite
Unakite (Epidotized Granite)
Unakite
Unakite (Metamorphosed granite)
Chert (White Chert / Flint)
Microcrystalline or Cryptocrystalline Silicon Dioxide (SiO2)
Opal
Hydrated Silica (SiO2·nH2O)
Jasper
Silicon Dioxide (Microcrystalline Quartz / Chalcedony)
Red Jasper
Silicon Dioxide (SiO2) with Hematite impurities
Fluorite
Calcium Fluoride (CaF2)
Chert (Flint)
Chert (microcrystalline quartz)
Rhodonite
Manganese Silicate (Mn,Fe,Mg,Ca)SiO3
Conglomerate
Conglomerate (clastic sedimentary rock)
Pearl
Aragonite (CaCO3 with conchiolin)
Larimar
Pectolite (a variety of pectolite, NaCa2Si3O8(OH))
Yellow Chert
Sedimentary cryptocrystalline quartz (SiO2)
Quartz
Silicon Dioxide (SiO2)
Quartz
Silicon Dioxide (SiO2)