Sandstone Concretion
Septarian Concretion (Nodule)
Category
Browse mineral (chalcedony) specimens identified by the Rock Identifier community.
Sandstone Concretion
Septarian Concretion (Nodule)
Iron-Stained Quartz (Riverside Cobble)
Silicon Dioxide (SiO2) with Limonite/Hematite inclusions
Quartz with inclusions
SiO2
Malachite
Malachite (Cu2(CO3)(OH)2 - a copper carbonate hydroxide mineral)
Shale with Iron Oxide Staining
Fissile Mudstone (primarily clay minerals and quartz)
River Cobble (likely Siltstone or Sandstone)
Clastic Sedimentary Rock
Chert (with Quartz vein/coating)
Microcrystalline Quartz (SiO2)
Diorite
Diorite (an intrusive igneous rock)
Garnetiferous Quartzite (Garnet Gneiss Pebble)
Garnet-bearing Quartzite or Quartz-Feldspar Gneiss
Sandstone (Graywacke)
Clastic Sedimentary Rock (Lithic Sandstone)
Quartz Pebble
Silicon Dioxide (SiO2)
Gneiss
Gneiss (High-grade Regional Metamorphic Rock)
Orthoclase Feldspar
KAlSi3O8 (Potassium Aluminum Silicate)
Graphite
Graphite (Native Carbon, C)
Quartz Pebble
Silicon Dioxide (SiO2)
Blue Apatite
Fluorapatite (Ca5(PO4)3F)
Banded Gneiss
Gneiss
Granite
Granite (a plutonic igneous rock composed primarily of quartz, feldspar, and mica)
Amygdaloidal Basalt
Amygdaloidal Basalt (Mafic Volcanic Rock)
Basalt
Mafic Igneous Rock (primarily Plagioclase Feldspar and Pyroxene)
Granite
Phaneritic Felsic Igneous Rock
Feldspar-rich Pegmatite
Granitic Pegmatite (principally KAlSi3O8)
Clay (as a rock-forming material)
Clay minerals (e.g., Kaolinite group, Smectite group, Illite group, Chlorite group)
Basalt with Calcite Veining
Aphanitic Mafic Igneous Rock (primarily Plagioclase and Pyroxene)
Turquoise
Hydrated phosphate of copper and aluminium [CuAl6(PO4)4(OH)8·4H2O]
Red Sandstone
Arenite (primarily SiO2 with hematite/iron oxide coating)
Ironstone Concretion / Limonite-stained Siltstone
Ironstone (primarily Limonite FeO(OH)·nH2O and Siltstone)
Magnetite
Magnetite (Iron(II,III) oxide, Fe3O4)
Basalt with Epidote/Chlorite
Amygdaloidal Basalt (SiO2 with (Ca2(Al2,Fe)(SiO4)(Si2O7)O(OH)))
Quartz (Milk Quartz Cobble)
Silicon Dioxide (SiO2)
Basalt Porphyry
Porphyritic Basalt
Pink Marble or Rose Quartz (Likely Pink Marble based on carving texture)
Recrystallized Calcite (CaCO3)
Granite (Fine-grained)
Phaneritic Felsic Igneous Rock
Pyrite in Quartz (Drill Core)
Silicon Dioxide (SiO2) with Iron Sulfide (FeS2) inclusions
Muscovite Mica
Muscovite (KAl₂(AlSi₃O₁₀)(F,OH)₂))
Granite Pebble
Granite (a plutonic igneous rock composed primarily of quartz, feldspar, and mica/amphibole)
Green Apophyllite and Stilbite on Quartz Cluster
Apophyllite-(K) (KCa4(Si8O20)(F,OH)·8H2O), Stilbite-Ca (NaCa4(Si27Al9)O72·28H2O), Quartz (SiO2)
Sandstone (Quartz Arenite)
Sandstone (SiO2 with possible mineral cements)
Prehnite
Prehnite - Ca2Al(AlSi3O10)(OH)2
Granite
Granite
Man-made Synthetic Material (Costume Faux Fur)
Synthetic Polymer (Polyester/Acrylic)
Peach Aventurine
Silicon Dioxide (SiO2) with inclusions