Geode or Concretion
Silica-based Concretion / Quartz Geode
sedimentary
Category
Mineral Based Composite
Browse mineral based composite specimens identified by the Rock Identifier community.
Learn about Mineral Based Composite in the encyclopedia
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Diamond (Princess Cut Faceted Gemstone)
Native Carbon (C)
mineral
Blue Kyanite
Kyanite (Al2SiO5)
mineral
Sandstone (Pebble)
Sandstone (SiO2 dominated clastic sedimentary rock)
sedimentary
Glauconitic Sandstone (Greensand)
Glauconitic Sandstone ((K, Na)(Fe3+, Al, Mg)2(Si, Al)4O10(OH)2)
sedimentary
Sandstone
Arenite (primarily Quartz Arenite)
sedimentary
Yellow Aventurine
Silicon Dioxide (Quartz with inclusions), SiO2
mineral
Sandstone
Arenite (SiO2 based with quartz grains)
sedimentary
Diamond
C (Carbon)
mineral
Sandstone
Arenite (primarily Quartz-based Sandstone)
sedimentary
Sandstone (likely Arkosic or Lithic)
Clastic Sedimentary Rock (composed predominantly of sand-sized grains, 0.0625 to 2 mm)
sedimentary
Sandstone (Quartzose)
Arenite (primarily SiO2)
sedimentary
Hag Stone (Sandstone with Boreholes)
Bored Sandstone (Sedimentary rock with lithophaga-style borings)
sedimentary
Conglomerate (or Breccia / Porphyry)
Clastic Sedimentary Rock (Conglomerate / Sandstone)
sedimentary
Sandstone (Quartzose Sandstone)
Arenite (primarily SiO2)
sedimentary
Red Sandstone (Iron-Rich)
Arenite (Fe2O3)
sedimentary
Cone-in-cone structure (Limestone)
Cone-in-cone structure (Secondary Sedimentary Structure)
sedimentary
Small rough quartz-family crystal specimens, including likely amethyst and citrine
Quartz, silicon dioxide (SiO₂); purple specimen is likely amethyst, yellow specimen likely citrine or iron-stained quartz
mineral
Sandstone
Sedimentary Rock (Quartz arenite / Lithic sandstone)
sedimentary
Chrysocolla Cuprite
Cu2-xAlx(H2-xSi2O5)(OH)4·nH2O (Chrysocolla) and Cu2O (Cuprite)
mineral composite
Blue Sapphire (in a faceted jewelry setting)
Corundum (Al2O3) with trace Iron and Titanium
mineral
Amethyst
Silicon Dioxide (SiO2) with iron impurities
mineral
Copper-bearing volcanic breccia
Altered andesite or rhyolite breccia with secondary copper minerals, likely chrysocolla and/or malachite
igneous
Orange Quartzite / Carnelian Agate
Silicon Dioxide (SiO2)
metamorphic
Sandstone with Secondary Mineral Encrustation
Arenite with Silica/Calcite deposits (SiO2 or CaCO3)
sedimentary
Turquoise ring stone (likely stabilized or dyed turquoise)
Turquoise — hydrated copper aluminum phosphate, CuAl₆(PO₄)₄(OH)₈·4H₂O
gemstone
Dalmatian Jasper
Peralkaline Quartz-Feldspar Igneous Rock with Arfvedsonite
igneous
Rose Quartz
Silicon Dioxide (SiO2) with trace Titanium, Manganese, or Iron
mineral
Serpentinite
Serpentinite (composed primarily of Serpentine group minerals, Mg3Si2O5(OH)4)
metamorphic
Blue Chalcedony
Chalcedony (SiO2)
mineral
Sandstone (likely Ferruginous)
Sandstone (SiO2 with iron oxides)
sedimentary
Chevron amethyst point
Quartz, SiO₂, with purple amethyst and white quartz zoning
gemstone
Mica Schist
Mica Schist
metamorphic
Sandstone with Iron Staining
Arenite (SiO2 based with Fe2O3 staining)
sedimentary
Sandstone
Arenite (primarily SiO2)
sedimentary
Sandstone (likely Graywacke or Siltstone variety)
Clastic Sedimentary Rock (SiO2 with assorted mineral fragments)
sedimentary
Red Sandstone
Arenite (primarily SiO2 with Fe2O3)
sedimentary
Fluorite (Green Fluorite on Host Rock)
Fluorite (Calcium Fluoride, CaF2)
mineral
Green Fluorite
Calcium Fluoride (CaF2)
mineral
Sandstone
Sandstone (SiO2 dominant)
sedimentary
Weathered concrete or cementitious slab (not natural rock)
Artificial calcium-silicate cement composite; likely Portland cement concrete
sedimentary
Gold
Gold (Au)
mineral