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)
Blue Apatite
Fluorapatite (Ca5(PO4)3F)
Tahitian Pearl
Biogenic Calcium Carbonate (Aragonite/Calcite), CaCO3
Citrine
Silicon dioxide (SiO2) - yellow quartz variety
Petrified Wood
Silicified Wood (SiO2)
Aquamarine
Beryl (Be3Al2Si6O18 with trace Fe2+)
Tanzanite
Blue Zoisite (Ca2Al3(SiO4)(Si2O7)O(OH))
Petrified Wood
Silicified wood (principally Silicon Dioxide, SiO2)
Petrified Wood
Silicified Wood (SiO2)
Chert / Flint
Microcrystalline Quartz (SiO2)
Chert (often called Flint)
Cryptocrystalline Quartz (SiO2)
Chert (Nodule)
Silicon Dioxide (SiO2)
Chert (Jasper/Flint variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Blue Chalcedony
Silicon Dioxide (SiO2)
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 Pebble with Quartz Veins
Microcrystalline Quartz (SiO2)
Chert (Jasper/Flint variety)
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)
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)