Ironstone Concretion / Limonite-stained Siltstone
Ironstone (primarily Limonite FeO(OH)·nH2O and Siltstone)
Category
Browse mineral (biogenic) specimens identified by the Rock Identifier community.
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 Pebble
Quartz (Silicon Dioxide, SiO2)
Blue Apatite
Apatite group (Ca5(PO4)3(F,Cl,OH))
Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
Gneiss (Metamorphic Cobble)
Gneiss
Blue Apatite
Apatite (Calcium Phosphate) - Ca5(PO4)3(F,Cl,OH)
Quartz Pebble
Silicon Dioxide (SiO2)
Blue Apatite
Fluorapatite (Ca5(PO4)3F)
Unakite
Epidotized Granite
Blue Apatite
Apatite-(CaF), Ca5(PO4)3F
Quartz (Milky Quartz / Quartzite)
Silicon Dioxide (SiO2)
Quartz Pebble
Silicon Dioxide (SiO2)
Gneiss
Gneiss (High-grade metamorphic rock)
Sandstone (Green/Yellow Siltstone variant)
Arenite or Siltstone (primarily SiO2 with mineral staining)
Pegmatite (Granitic)
Granitic Pegmatite containing Quartz, Feldspar, and Tourmaline (Schorl)
Garnetiferous Quartzite (Garnet Gneiss Pebble)
Garnet-bearing Quartzite or Quartz-Feldspar Gneiss
Basalt with Amygdules
Amygdaloidal Basalt
Basalt with Quartz Vein
Mafic Igneous Rock (SiO2 filling)
Quartz (White/Milky Pebble)
Silicon Dioxide (SiO2)
Orange Calcite
Calcite (CaCO3)
Gneiss (with Quartzite and Biotite)
Gneiss containing SiO2 (Quartz), K(Mg,Fe)3AlSi3O10(OH)2 (Biotite), and (K,Na,Ca)AlSi3O8 (Feldspar)
Green Aventurine
Silicon Dioxide (SiO2) with inclusions of Fuchsite mica
Garnet
Garnet Group (Silicate Minerals), formula varies e.g., Almandine Fe3Al2(SiO4)3
Sandstone (Quartzose)
Arenite (primarily SiO2)
Conglomerate
Conglomerate (clastic sedimentary rock)
Hypersthene (or Enstatite/Ferrosilite)
Orthopyroxene series (Mg,Fe)SiO3 - specifically, historically hypersthene (intermediate member) now referred to as Enstatite (Mg-rich) or Ferrosilite (Fe-rich)
Olivine (Peridot)
Olivine Group (Mg,Fe)2SiO4
Sandstone (Ferruginous)
Arenite with Iron-Oxide Cement
Schist
Mica Schist
Garnet (specifically Almandine)
Almandine - Fe3Al2(SiO4)3
Amazonite
Potassium Feldspar (KAlSi3O8)
Pyrite in Quartz
FeS2 (Iron Pyrite) with SiO2 (Quartz)
Schist
Mica Schist
Amygdaloidal Basalt
Basalt with secondary mineral infilling (commonly Zeolite, Calcite, or Quartz)
Granite Pebble
Granite (Phaneritic Quartz-Feldspar Rock)
Chrysocolla in Jasper (Chryso-Jasper)
Cu2-xAlx(H2-xSi2O5)(OH)4·n H2O (Chrysocolla) + SiO2 (Jasper)
Green Calcite
Calcite (CaCO3)
Larimar
Pectolite (a blue variety of Pectolite)
Turquoise
Turquoise (Hydrated copper aluminum phosphate, CuAl6(PO4)4(OH)8·4H2O)
Amethyst
SiO2 (Silicon Dioxide with iron impurities)