Chert (Tan/Yellow variety)
Microcrystalline Quartz (SiO2)
Category
Browse organic gemstone specimens identified by the Rock Identifier community.
Chert (Tan/Yellow variety)
Microcrystalline Quartz (SiO2)
Chert (with small quartz vug)
Chert (SiO2)
Chert (Flint)
Chert (Cryptocrystalline Silicon Dioxide, SiO2)
Chert (and Jasper pebble)
Microcrystalline Silica (SiO2)
Petrified Wood
Silicified Wood (primarily Chalcedony or Quartz, SiO2)
Chert (Yellow Jasper/Agatized Chert)
Microcrystalline Quartz (SiO2)
Chert (White Chert / Flint)
Microcrystalline or Cryptocrystalline Silicon Dioxide (SiO2)
Petrified Wood
Silicified Wood (primarily Quartz/Chalcedony, SiO2)
Petrified Wood
Silicified Wood (SiO2)
Sandstone Chert Concretion
Silica-cemented Concretion (primarily SiO2)
Moss Agate
Silicon Dioxide (SiO2) with inclusions of manganese or iron oxide
Chert (specifically Gray Chert)
Silicon Dioxide (SiO2)
Sandstone with Vitrinite/Coal inclusions
Arenite with Carbonaceous inclusions
Amber
Succinite (specifically Baltic Amber) - Formula: C10H16O (approximate)
Chert / Flint (with Crinoid Stem Molds)
Microcrystalline Quartz (SiO2)
Amber
Succinite (C10H16O)
Amber
Succinite (specifically for Baltic amber); approximate formula C10H16O
Amber
Succinite (specifically for Baltic Amber), Formula: C10H16O
Ferruginous Sandstone Concretion (Ironstone Phosphorite)
Ferruginous Sandstone (variable Fe-oxide/hydroxide composition)
Hypersthene
Hypersthene ((Mg,Fe)SiO3)
Chert (often called Flint)
Chert (Microcrystalline Silicon Dioxide, SiO2)
Petrified Wood (Agatized/Silicified Wood)
Silicified Paleoxylon (primarily SiO2)
Petrified Wood
Silicified Wood (primarily SiO2)
Fossiliferous Limestone
Biogenic Limestone (Calcium Carbonate, CaCO3)
Black Chert (Flint)
Microcrystalline Quartz (SiO2)
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2 with inclusions)
Aquamarine
Beryl (Be3Al2Si6O18)
Ironstone Concretion
Siderite or Hematite Concretion
Chert
Chert (Microcrystalline Quartz, SiO2)
Fossil Shark Tooth
Odontaspididae (likely Carcharias sp.)
Chert (variations include Flint)
Silicon Dioxide (SiO2)
Chert (Flint)
Silicon Dioxide (SiO2)
Chert (River Pebble)
Microcrystalline Quartz (SiO2)
Chert (Beach Pebble)
Silicon Dioxide (SiO2)
Oyster Shell Fragment
Crassostrea virginica (or related Bivalvia)
Chert (Carnelian/Jasper variety)
Microcrystalline Quartz (SiO2)
Petrified Bone Pebble
Silicified Fossilized Bone
Petrified Wood
Silicified Wood (primarily SiO2)
Anthracite Coal
Anthracite
Chert (White Chert/Flint)
Silicon Dioxide (SiO2)
Quartz Geode
Crystalline Silicon Dioxide (SiO2) in sedimentary/volcanic host
Chert (often called Flint)
Silicon Dioxide (SiO2)