Turtle Stone / Septarian Nodule (Water-worn)
Septarian Concretion
Category
Browse organic structure (not a rock) specimens identified by the Rock Identifier community.
Turtle Stone / Septarian Nodule (Water-worn)
Septarian Concretion
Petrified Wood
Silicified Wood (primarily Quartz/Chalcedony replacing $SiO_2$)
Chert (specifically Flint or Jasperoid)
Silicon Dioxide (SiO2)
Chert (Pink Jasper variant)
Microcrystalline Quartz (SiO2)
Chert (specifically Flint or Jasper variant)
Microcrystalline quartz (SiO2)
Chert (Flint)
Silicon Dioxide (SiO2)
Natural or Cultured Pearl
Calcium Carbonate (Aragonite and Conchiolin), CaCO3
Chert (containing Fossil Inclusions)
Microcrystalline Quartz (SiO2)
Basalt
Extrusive Igneous Rock
Quartz Crystal Cluster on Matrix
Silicon Dioxide (SiO2)
Quartz Crystal on Matrix
Silicon Dioxide (SiO2)
Quartz Druzy (on Matrix)
Silicon Dioxide (SiO2)
Chert Nodule
Microcrystalline Quartz (SiO2)
Fossilized Crinoid Stem Segment
Crinoid (Phylum Echinodermata, Class Crinoidea)
Dalmatian Stone
Aplite (often incorrectly called Dalmatian Jasper)
Chert (Jasper)
Microcrystalline Quartz (SiO2)
Chert (Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Tan/Brown variety)
Chert (Microcrystalline Quartz, SiO2)
Chert (Jasper/Flint variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Fossil Plant Impression (Calamites)
Calamites sp. (Tracheophyta: Equisetopsida)
Petrified Wood
Silicified Wood (SiO2)
Chert (specifically Flint or Common Chert)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (varietal Flint or Jasper)
Microcrystalline Quartz (SiO2)
Chert (Flint variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Eclogite
Eclogite (Omphacite-Garnet rock)
Sandstone
Arenite
Chert / Jasper
Microcrystalline Quartz (SiO2)
Geode with Quartz and possibly Jasper/Hematite
Quartz (SiO2) and Chalcedony (cryptocrystalline SiO2), possibly stained by iron oxides
Granite
Intrusive Igneous Rock
Fossil Shark Tooth
Chondrichthyes (Class)
Petrified Wood
Silicified Wood (SiO2)
Mixed Quartz and Jasper Pebbles
Silicon Dioxide (SiO2)
Chert (Nodule)
Silicon Dioxide (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Chert (varieties include Flint and Jasper)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Yellow Jasper/Flint pebble)
Microcrystalline Quartz (SiO2)
Breciated Jasper
Silicon Dioxide (SiO2) with iron oxide inclusions
Jasper and Quartz Breccia
Silicified Breccia (Quartz / Chalcedony / Hematite)
Agate (specifically a Yellow/Honey Agate)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Moqui Marble (Shaman Stone)
Iron Oxide Concretion (composed primarily of Quartz sand with Hematite/Goethite shell)
Picasso Jasper (or Picasso Marble)
Metamorphosed Limestone (Calcium Carbonate, CaCO3, with impurities)