Concretion
Septarian Concretion (Fragmentary)
sedimentary
Category
Mineral Based Composite
Browse mineral based composite specimens identified by the Rock Identifier community.
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Unknown Organic Object (likely a berry or fruit)
Not applicable; this is not a geological specimen. If it were a cranberry, its scientific name would be Vaccinium macrocarpon; if a cherry, it would be Prunus avium or Prunus cerasus.
Organic Material (likely a fruit or berry)
Rough Diamond
Diamond (pure Carbon, C)
mineral
Green Aventurine
Aventurine Quartz (SiO2 with Fuchsite inclusions)
mineral
Aquamarine
Beryl (Be3Al2Si6O18 with iron impurities)
mineral
Quartz pebble
Silicon Dioxide (SiO2)
mineral
Smoky Quartz Cluster
Smoky Quartz (Silicon Dioxide - SiO2)
mineral
Epidote
Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)
Mineral
Cinnabar in Quartz
Silicon Dioxide (SiO2) with Mercury Sulfide (HgS) inclusions
Mineral
Sandstone (with banding/weathering)
Clastic Sedimentary Rock (primarily SiO2)
sedimentary
Aragonite (specifically Mexican Marbled Onyx)
Aragonite (Calcium Carbonate, CaCO3)
mineral
Rhodonite Tumbled Chips
Manganese silicate (Mn,Fe,Mg,Ca)SiO3
mineral
Plume Agate or Moss Agate
Agate (SiO2)
mineral
Conglomerate
Clastic Sedimentary Rock (Conglomerate)
sedimentary
Sandstone
Arenite (SiO2 primarily)
sedimentary
N/A (The provided image is a storyboard/digital document)
N/A
Tumbled milky quartz
Quartz, silicon dioxide (SiO₂)
mineral
Polished honey/pink calcite heart
Calcite, calcium carbonate (CaCO₃)
mineral
Weathered iron-rich stone, possibly limonite-bearing rock
Limonite/goethite mixture (hydrated iron oxides), identification uncertain from image
mineral
Likely calcite fragment
Calcite (CaCO₃), possibly limestone or marble
mineral
Blue calcite (probable)
Calcite — CaCO₃
mineral
Small brown-gray mineral fragment
Indeterminate; possibly weathered quartz-, feldspar-, or iron-oxide-bearing rock
mineral
Marble
Metamorphic rock composed of Recrystallized Carbonate Minerals (chiefly CaCO3)
metamorphic
Quartzite (or Quartz Slab)
SiO2 (Silicon Dioxide)
metamorphic
Likely weathered stone or mineral fragment
Unidentified fine-grained silicate rock; possible basalt, greenstone, or serpentine
mineral
Tumbled serpentine (likely bowenite)
Serpentine-group magnesium silicate; commonly antigorite, lizardite, or chrysotile (Mg₃Si₂O₅(OH)₄)
mineral
Sandstone
Arenite
sedimentary
Jasper (likely a variety of Yellow or Mustard Jasper)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
sedimentary (chemically precipitated mineral)
Pyrite Concretion (Grapestone)
Iron Sulfide (FeS2) Concretion
sedimentary
Gold Nugget
Native Gold (Au)
mineral
Sandstone Clast
Arenite (primarily SiO2)
sedimentary
Raw turquoise-bearing rock
Turquoise, CuAl₆(PO₄)₄(OH)₈·4H₂O, likely in a limonite/matrix host
mineral
Gastly (Trick or Trade Halloween Series)
Cellulose-carbonaceous composite (Lignocellulose laminated with pigmentary polymers)
Mineral (Synthetic - Paper and Ink Polymorph)
Polished gray stone, likely quartzite or river-worn granite
Tentatively quartzite (mostly microcrystalline SiO₂); exact identification is uncertain from the photograph
metamorphic
Sandstone
Arenite (SiO2-rich)
sedimentary
Basalt
Basalt (Mafic volcanic rock)
igneous
Bronzite
Enstatite (magnesium iron silicate), (Mg,Fe2+)SiO3
mineral
Black Tourmaline (Schorl)
Schorl (Sodium iron silicate hydroxide boron silicate); NaFe3Al6(BO3)3Si6O18(OH)4
mineral
Gold Nugget
Gold (Au)
mineral
Unidentified Dark Mineral or Rock
Indeterminate (Likely Silicon Dioxide or Carbon-based)
mineral
River Stone (Quartzite/Siltstone mixture)
Silicon Dioxide (SiO2) based metamorphosed sandstone
metamorphic or sedimentary
Conglomerate
Conglomerate (clastic sedimentary rock)
sedimentary