Chert (Iron-stained)
Chert / Microcrystalline Silicon Dioxide (SiO2)
Category
Browse organic (often found by beachcombers) specimens identified by the Rock Identifier community.
Chert (Iron-stained)
Chert / Microcrystalline Silicon Dioxide (SiO2)
Chert (Iron-stained)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert / Flint
Silicon Dioxide (SiO2)
Chert (Tan/Yellow variety)
Microcrystalline quartz (SiO2)
Chert (Green variety)
Chert (Silicon Dioxide, SiO2)
Ferruginous Sandstone (with possible trace fossils)
Arenite with Iron-Oxide Cement (SiO2 with Fe2O3)
Chert (Black Flint)
Silicon Dioxide (SiO2)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Chert (and Jasper/Flint variant)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Nodule)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Flint variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Yellow Chert
Microcrystalline Quartz (SiO2)
Red Chert (Jasper)
Silicon Dioxide (SiO2)
Fossilized Coprolite
Coprolite (fossilized feces)
Chert (often called Flint when in chalk or limestone)
Silicon Dioxide (SiO₂)
Chert (Nodule)
Silicon Dioxide (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Chert (Yellow Jasper/Flint)
Microcrystalline Quartz (SiO2)
Fossilized Brain Coral
Diploria labyrinthiformis (Fossilized)
Bituminous Coal
Bituminous coal (Organic Sedimentary Rock)
Chert (often called Flint)
Silicon Dioxide (SiO2)
Coral Fossil (Agatized Coral or Petoskey Stone)
Hexagonaria percarinata (if Petoskey) or generally Scleractinia (Agatized Coral)
Chert (often called Flint when dark)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Jasper/Flint variety)
Microcrystalline quartz (SiO2)
Red Jasper
Jasper (Silicon Dioxide, SiO2 with iron oxide impurities)
Chert (varietal: Flint or River Pebble)
Silicon Dioxide (SiO₂)
Ironstone Concretion
Siderite or Limonite Concretion (FeCO3 or FeO(OH)·nH2O)
Geode (unopened)
Chert / Chalcedony Geode (SiO2)
Turquoise, Pearl, and Coral Necklace
CuAl6(PO4)4(OH)8·4H2O (Turquoise) / CaCO3 (Pearl and Coral)
Chert (Lightly weathered variety)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Chert (Nodule)
Chert (primarily Microcrystalline Quartz - SiO2)
Chert (Jasper variation)
Microcrystalline Quartz (SiO2)
Banded Chert
Microcrystalline Quartz (SiO2)
Chert (Jasper/Flint variety)
Microcrystalline Quartz (SiO2)
Chert (Gravel pebble)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Petrified Wood
Silicified Wood (primarily SiO2 - Silicon Dioxide)
Chert (Jasper/Flint variety)
Microcrystalline Quartz (SiO2)
Chert with Quartz Vein
Microcrystalline Quartz (SiO2)
Pink Opal
Hydrated Silica (SiO2·nH2O)
Tahitian Pearl
Biogenic Calcium Carbonate (Aragonite/Calcite), CaCO3
Pink Opal
Amorphous Hydrous Silica (SiO2·nH2O)
Petrified Wood
Silicon Dioxide (SiO2) permineralized organic matter