Chert (and/or River Pebble)
Microcrystalline quartz (SiO2)
Category
Browse mineral, organic gemstone specimens identified by the Rock Identifier community.
Chert (and/or River Pebble)
Microcrystalline quartz (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Tanzanite
Blue Zoisite (Ca2Al3(SiO4)(Si2O7)O(OH))
Blue Apatite
Fluorapatite (Ca5(PO4)3F)
Tahitian Pearl
Biogenic Calcium Carbonate (Aragonite/Calcite), CaCO3
Chert / Flint
Microcrystalline Quartz (SiO2)
Chert (often called Flint)
Cryptocrystalline Quartz (SiO2)
Citrine
Silicon dioxide (SiO2) - yellow quartz variety
Aquamarine
Beryl (Be3Al2Si6O18 with trace Fe2+)
Petrified Wood
Silicified wood (principally Silicon Dioxide, SiO2)
Petrified Wood
Silicified Wood (SiO2)
Blue Chalcedony
Silicon Dioxide (SiO2)
Chert (Nodule)
Silicon Dioxide (SiO2)
Chert (Jasper/Flint variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Black Jasper
Black Jasper (Silicate mineral - SiO2)
Chert (Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (variant Flint/Jasper)
Microcrystalline Opaline Silica (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Petrified Wood
Silicified Wood (primarily SiO2)
Chert (specifically Flint or Jasper variant)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (often found as Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Flint variety)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Chert (Jasper/Flint variety)
Microcrystalline Quartz (SiO2)
Chert Pebble with Quartz Veins
Microcrystalline Quartz (SiO2)
Green Apatite on Albite
Fluorapatite [Ca5(PO4)3F] on Albite [Na(AlSi3O8)]
Shale (with minor calcite veining)
Clastic sedimentary rock (primarily clay minerals and quartz)
Pink Opal
Hydrated Silica (SiO2·nH2O)
Moss Agate
Chalcedony (SiO2) with inclusions of manganese or iron oxides
Chert (Flint)
Chert (Silicon Dioxide, SiO2)
Fossiliferous Shale
Laminated Mudrock with plant fossils
Shale
Shale (Sedimentary rock composed of mud/clay minerals)
Pearl (as a biogenic mineral/gemstone)
Calcium Carbonate (mostly Aragonite), CaCO3
Jasper
Cryptocrystalline Quartz (SiO2)
Rough Emerald
Emerald (Beryl), Be3Al2(SiO3)6
Chert (varietal: Flint/Jasper mix)
Hydrous Silica (SiO2)
Sandstone (Weathered Coastal Boulder)
Arenite (composed primarily of SiO2)
Petrified Wood
Silicified Wood (SiO2)
Graphite-veined Quartzite
Meta-sedimentary Quartzite with Carbonaceous/Graphitic Inclusions (SiO2 + C)
Jasper with Quartz Vein
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Chert (with Limestone and Iron Oxide staining)
Cryptocrystalline Quartz (SiO2)
Petrified Wood
Silicified Wood (SiO2 - Silicon Dioxide)
Petrified Wood
Silicon Dioxide (SiO2) permineralized organic matter