Chert (Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Category
Browse mineral and organic gemstone specimens identified by the Rock Identifier community.
Chert (Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Petrified Wood
Silicified Wood (primarily SiO2)
Black Jasper
Black Jasper (Silicate mineral - SiO2)
Chert (specifically Flint or Jasper variant)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (variant Flint/Jasper)
Microcrystalline Opaline Silica (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Chert (often found as Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Green Apatite on Albite
Fluorapatite [Ca5(PO4)3F] on Albite [Na(AlSi3O8)]
Chert (Jasper/Flint variety)
Microcrystalline Quartz (SiO2)
Chert Pebble with Quartz Veins
Microcrystalline Quartz (SiO2)
Chert (Flint variety)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Shale (with minor calcite veining)
Clastic sedimentary rock (primarily clay minerals and quartz)
Moss Agate
Chalcedony (SiO2) with inclusions of manganese or iron oxides
Chert (Flint)
Chert (Silicon Dioxide, SiO2)
Pink Opal
Hydrated Silica (SiO2·nH2O)
Shale
Shale (Sedimentary rock composed of mud/clay minerals)
Fossiliferous Shale
Laminated Mudrock with plant fossils
Chert (varietal: Flint/Jasper mix)
Hydrous Silica (SiO2)
Pyrite
Iron Sulfide (FeS2)
Graphite
Graphite (Carbon, C)
Jasper
Cryptocrystalline Quartz (SiO2)
Pearl (as a biogenic mineral/gemstone)
Calcium Carbonate (mostly Aragonite), CaCO3
Rough Emerald
Emerald (Beryl), Be3Al2(SiO3)6
Aquamarine
Beryl (Be3Al2Si6O18)
Sandstone (Weathered Coastal Boulder)
Arenite (composed primarily of SiO2)
Petrified Wood
Silicified Wood (SiO2)
Chert (with Limestone and Iron Oxide staining)
Cryptocrystalline Quartz (SiO2)
Moonstone
Orthoclase feldspar ((K,Na)AlSi3O8)
Jasper with Quartz Vein
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Graphite-veined Quartzite
Meta-sedimentary Quartzite with Carbonaceous/Graphitic Inclusions (SiO2 + C)
Chert (Limestone-based)
Silicon dioxide (SiO2)
Chert / Flint
Chert (Silicon Dioxide, SiO2)
Petrified Wood
Silicified Wood (SiO2 - Silicon Dioxide)
Petrified Wood
Silicon Dioxide (SiO2) permineralized organic matter
Fossil Coral (Favosites)
Favosites (Order: Tabulata, Phylum: Cnidaria)
Petrified Wood
Silicified Wood (SiO2)
Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
Travertine (used in construction, not a 'specimen' in situ)
Travertine
Black Marble
Recrystallized Calcite (CaCO3)
Chert (Jasper/Flint variety)
Microcrystalline quartz (SiO2)
Septarian Nodule (Thunder Egg)
Septarian Concretion (CaCO3 + CaMg(CO3)2 + SiO2)
Petrified Wood
Silicified Wood (SiO2 - primarily Quartz/Chalcedony/Opal)