Sandstone with Secondary Mineral Encrustation
Arenite with Silica/Calcite deposits (SiO2 or CaCO3)
sedimentary
Category
Organic Materia (Not A Rock Or Mineral)
Browse organic materia (not a rock or mineral) specimens identified by the Rock Identifier community.
Learn about Organic Materia (Not A Rock Or Mineral) in the encyclopedia
View all →
Granite
Phaneritic plutonic rock (SiO2 rich)
igneous
Educational Geologic Collection
Mixed Mineral and Rock Collection (Various compositions)
mineral
Mixed river-worn rock and mineral collection
Mostly quartz/quartzite, feldspar-bearing granitoid, chert, and mafic volcanic rocks; exact species vary by pebble
igneous, sedimentary, metamorphic, mineral
Decorative polished pebbles
Likely mixed quartz-rich lithologies, including quartzite, jasper, and/or basalt
mineral
Petrified Wood (Agatized/Silicified Wood)
Silicified Wood / Chalcedony (SiO2)
sedimentary
Veined Sandstone with Calcite Veins
Sedimentary sandstone with hydrothermal/mineral veins
sedimentary
Banded Gneiss Pebble
Gneiss (Metamorphic Rock)
metamorphic
Rough turquoise-bearing rock (probable turquoise matrix)
Turquoise, CuAl₆(PO₄)₄(OH)₈·4H₂O, likely in a host-rock matrix
mineral
Sandstone (with potential mineral staining/concretions)
Arenite (SiO2 based)
sedimentary
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Conglomerate
Conglomerate Rock
sedimentary
Unidentified gray rock/mineral specimen
Indeterminate; possibly quartz-rich rock or a metallic sulfide-bearing specimen
mineral
Basalt with Quartz/Calcite Veins
Aphanitic Mafic Igneous Rock (Hydrothermal Veined)
igneous
Septarian Nodule (Micro-fragment)
Septarian Nodule / Concretion (CaCO3 + CaMg(CO3)2 + Quartz)
sedimentary
Chert (Yellow Jasper variant)
Microcrystalline Quartz (SiO2)
sedimentary
Leopard Skin Jasper
Orbicular Jasper (Silicon Dioxide, SiO2)
sedimentary
Glauconitic Sandstone (Greensand pebble)
Glauconitic Quartz Sandstone (K(Fe,Al)2(Si,Al)4O10(OH)2)
sedimentary
Chert (specifically Gray/Black Chert)
Chert (Microcrystalline or Cryptocrystalline Quartz, SiO2)
sedimentary
Chert Pebble (Jasper/Quartz variety)
Microcrystalline Quartz (SiO2)
sedimentary
Vesicular Basalt (Scoria)
Basalt with vesicular texture
igneous
Mookaite Jasper
Silicon Dioxide with Iron Oxide impurities (SiO2)
mineral
Chert with Quartz Veining
Microcrystalline Silica (SiO2)
sedimentary
Sandstone with Quartz Vein
Arenite with Crystalline Silica (SiO2)
sedimentary
Sandstone
Arenite
Sedimentary
River Pebble (likely Quartzite or Chert)
Sedimentary Clast (Silicon Dioxide dominant)
sedimentary
Sandstone
Sedimentary Rock (Quartz Sandstone)
sedimentary
Sandstone
Arenite (SiO2 principal)
sedimentary
Generic Rock Fragment
Rock Fragment
sedimentary
Fossilized Shark Tooth
Elasmobranchii dentition (calcium phosphate / hydroxyapatite)
fossil
Ironstone Concretion / Limonite Node
Ferruginous Sedimentary Rock (composed primarily of Limonite FeO(OH)·nH2O and Goethite)
sedimentary
Sandstone
Sedimentary Rock (Quartz Sandstone)
sedimentary
Chert (Iron-stained)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Chert / Flint
Microcrystalline Quartz (SiO2)
sedimentary
Chert (often called Flint)
Cryptocrystalline Quartz (SiO2)
sedimentary
Orange Calcite
Calcium Carbonate (CaCO3)
mineral
Green Calcite
Calcium Carbonate (CaCO3)
mineral
Chert (River Pebble)
Silicon Dioxide (SiO2)
sedimentary
Granite
Felsic intrusive igneous rock
igneous
Sandstone with Concretions / Liesegang Rings
Arenite with iron oxide banding
sedimentary
Sedimentary Rock Fragments
Clastic Sedimentary Rock
sedimentary
Quartz (or Chert/Flint)
Silicon Dioxide (SiO2)
mineral