White Marble
Recrystallized Calcite (CaCO3)
Category
Browse anthropogenic (man made material mimicking sedimentary rock) specimens identified by the Rock Identifier community.
White Marble
Recrystallized Calcite (CaCO3)
Blue chalcedony cabochon (probable)
Chalcedony, a cryptocrystalline variety of quartz; silicon dioxide, SiO₂
Chert
Microcrystalline silica (SiO2)
Sandstone
Arenite (composed primarily of Quartz: SiO2)
Siltstone Pebble
Siltstone (composed of microscopic quartz and clay minerals)
Goldstone (Synthetic Aventurescence Glass)
Cuprous Aventurescent Glass (Silicon Dioxide with Copper inclusions)
Possible basalt or iron-rich slag
Basalt (tentative; identification uncertain from image)
Faceted glass-like gemstone object
Likely synthetic glass or cubic zirconia; exact material cannot be confirmed from the image
Tumbled brown chalcedony or agate
Microcrystalline quartz (SiO₂), likely chalcedony; possibly iron-stained jasper or agate
Chert (Honey Chert / Flint)
Silicon Dioxide (SiO2)
Chert (Flint)
Chert (Silicon Dioxide, SiO2)
Chert (Jasper/Flint)
Silicon Dioxide (SiO2)
Flint / Chert Pebble
Microcrystalline Quartz (SiO2)
Chert (Chert / Flint Variety)
Microcrystalline / Cryptocrystalline Quartz (SiO2)
Unakite
Altered Granite (Epidotized Granite)
Tumbled epidote-bearing rock (likely epidote–quartz–feldspar aggregate)
Epidote-rich metamorphic rock; minerals likely epidote (Ca₂(Al,Fe)₃Si₃O₁₂(OH), quartz, feldspar, and dark amphibole/biotite)
Yellow cabochon gemstone, likely citrine or yellow glass imitation
Quartz (SiO₂), if natural citrine; visual evidence is insufficient to exclude man-made glass or resin
Chert (specifically Flint or Nodular Chert)
Silicon dioxide (SiO2)
Chert (Jasper/Flint var.)
Silicon Dioxide (SiO2)
Chert (often called Flint or River Stone)
Microcrystalline alpha-quartz (SiO2)
Fulgarite
Fulgurite (Lechatelierite / Vitrified Sand)
Sea Glass (Frosted Glass)
Amorphous Silica (SiO2) with various additives
Chert (Siltstone / Flint)
SiO2 (Cryptocrystalline Quartz)
Brecciated Jasper
Silicon Dioxide (SiO2) with iron oxide inclusions
Graphite
Graphite (Carbon, C)
Chalk
Calcium Carbonate (CaCO3)
Limestone
Sedimentary Rock (Primarily CaCO3)
Chert (Jasper variety)
Silicon Dioxide (SiO2)
Flint (chert) hand axe
Cryptocrystalline silica (SiO₂), worked into a bifacial stone tool
Sandstone
Clastic Sedimentary Rock
Chert (often called Flint)
Chert (Microcrystalline or cryptocrystalline Silica, SiO2)
Chert (specifically Flint)
Chert (SiO2)
Yellow Chert (Chalcedony)
Microcrystalline Quartz (SiO2)
Chert (specifically Yellow/Brown Chert or Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Fossiliferous Limestone
Limestone (composed primarily of calcite with included fossils CaCO3)
Goldstone (blue/black aventurine glass)
Man-made aventurine glass; silica glass containing metallic copper or other glittering inclusions
Bivalve Fossil (Shell Fragment)
Class Bivalvia (Calcium Carbonate - CaCO3)
Blue glass-like tumbled specimen
Most likely cobalt-blue slag glass or manufactured glass; not confidently identifiable as a natural mineral from the image
Chert (varieties include Flint and Jasper)
Silicon Dioxide (SiO2)
Sea Glass (Kelly Green)
Amorphous Silica (Silicon Dioxide with Iron/Chromium additives)
Black-and-white agate geode pendant
Agate (microcrystalline quartz, SiO₂), likely a hollow geode slice with chalcedony and drusy quartz
Granite
Granite (Felsic Plutonic Rock)