Diamond
Carbon (C)
Category
Browse mineral description (anthropogenic material) specimens identified by the Rock Identifier community.
Diamond
Carbon (C)
Opalite
Man-made glass (traditionally simulated Opal)
Limestone with Calcite Veins
Sedimentary Calcium Carbonate (CaCO3)
Red Sandstone
Arenite (primarily Quartz with Iron Oxide)
Tektite (Indochinite)
Tektite (High-silica natural glass)
Chert / Flint
Silicon Dioxide (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Polished orbicular granite
Granite, chiefly quartz, alkali feldspar, plagioclase, and biotite/amphibole
Greenstone
Metamorphic mafic rock (chlorite-actinolite-epidote schist)
Dinosaur Bone
Agatized Dinosaur Bone
Ironstone Concretion (Iron-rich Mudstone)
Siderite / Geothite concretion (FeCO3 / FeO(OH))
Quartz
Silicon Dioxide (SiO2)
Quartz
Silicon Dioxide (SiO2)
Quartz
Silicon Dioxide (SiO2)
Quartz
Silicon Dioxide (SiO2)
Quartz
Silicon Dioxide (SiO2)
Chert (Flint Nodules)
Microcrystalline Quartz (SiO2)
Sandstone with Quartz Vein
Arenite with Quartz (SiO2) protrusion
Sandstone
Arenite (SiO2 based)
Sandstone (Banded)
Arenite (primarily SiO2)
Sandstone
Arenite (primarily Quartz Arenite)
Sandstone
Clastic Sedimentary Rock
Quartz Pebble
Silicon Dioxide (SiO2)
Sandstone (Ferruginous)
Arenite (with Iron Oxides)
Red Sandstone
Sandstone (lithic arenite or arkose with iron oxide)
White quartz pebble
Quartz (SiO₂), likely milky quartz
Polished Ocean Jasper
Orbicular Jasper (variety of Chalcedony/Quartz, SiO2)
Petrified Wood
Silicified Wood (primarily SiO2)
Petrified Wood
Silicified Wood (primarily Quartz/Chalcedony, formula SiO2)
Quartz Pebble
Silicon Dioxide (SiO2)
Sandstone
Clastic sedimentary rock (Arenite)
White quartz pebble
Quartz (silicon dioxide, SiO₂)
Purple fluorite (likely cubic crystal aggregate)
Fluorite, calcium fluoride (CaF₂)
Clear Quartz (Faceted) or Cubic Zirconia / Glass imitation
SiO2 (if Quartz), ZrO2 (if Cubic Zirconia)
Schist
Mica Schist
Chert (with potential fossil inclusion)
Microcrystalline Quartz (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Dark gray basalt or andesite cobble
Fine-grained mafic to intermediate volcanic rock; commonly plagioclase feldspar, pyroxene, and possibly olivine
Sandstone
Arenite (predominantly SiO2)
Sandstone (likely Graywacke or Arkose)
Arenite
Sandstone
Arenite (SiO2 principal)
Sandstone (Quartzose)
Arenite (primarily SiO2)