Ferruginous Sandstone
Clastic Sedimentary Rock (Iron-rich)
Category
Browse organic gemstone (not a rock or mineral in the traditional sense, but bio mineralized material) specimens identified by the Rock Identifier community.
Ferruginous Sandstone
Clastic Sedimentary Rock (Iron-rich)
Sandstone (with potential Quartzite characteristics)
Clastic sedimentary rock (primarily SiO2)
Sandstone (Flagstone)
Arenite (composed primarily of SiO2)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Kyanite (Blue and Green varieties)
Kyanite (Al₂SiO₅)
Sodalite
Sodalite (Sodium Aluminum Silicate Chloride) - Na8(Al6Si6O24)Cl2
Rose Quartz
Silicon dioxide (SiO2) with trace amounts of titanium, iron, or manganese
Quartz (Milky/Common)
Silicon Dioxide (SiO2)
Yellow Quartz (Citrine or Iron-Stained Quartz)
Silicon Dioxide (SiO2)
Diamond
Carbon (C)
Sandstone (Quartzose type)
Arenite (primarily SiO2)
Red Sandstone (Old Red Sandstone)
Ferruginous Sandstone (SiO2 + Fe2O3)
Red Jasper
Jasper (Silicate mineral - SiO2)
Sandstone (Ferruginous)
Arenite (primarily SiO2 with Fe2O3 staining)
Basalt with Scoria/Vesicular Texture
Extrusive Mafic Igneous Rock (primarily Plagioclase Feldspar and Pyroxene)
Prehnite
Prehnite (Ca2Al2Si3O10(OH)2)
Milky Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
Sandstone
Arenite (primarily SiO2)
Turquoise
Hydrated phosphate of copper and aluminium [CuAl6(PO4)4(OH)8·4H2O]
Ferruginous Sandstone
Clastic sedimentary rock (primarily SiO2 with Fe2O3 cement)
Milky Quartz
Silicon Dioxide (SiO2)
Serpentine (Serpentinite)
Serpentinite (complex silicate group including lizardite, chrysotile, and antigorite)
Diorite
Diorite (Intermediate intrusive igneous rock)
Brick
Fired clay or Ceramic material (no specific mineralogical scientific name as it's a composite)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Amazonite
KAlSi3O8 (Potassium Feldspar, variety of Microcline)
Herkimer Diamond
Quartz (SiO2)
Turquoise
Hydrated phosphate of copper and aluminium, CuAl6(PO4)4(OH)8·4H2O
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2 with iron oxide inclusions)
Serpentine
Serpentinite (rock) containing serpentine minerals (e.g., Antigorite, Lizardite, Chrysotile)
Grey Agate (Tumbled)
Silicon Dioxide (SiO2)
Agate (or Chalcedony)
Silicon Dioxide (SiO2)
Schist
Mica Schist (primarily Muscovite [KAl2(AlSi3O10)(OH)2] or Biotite)
Sandstone (Ferruginous)
Ferruginous Sandstone (SiO2 with Fe2O3)
Epidote
Epidote (formula: Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH))
Feldspar
Potassium Feldspar (KAlSi3O8)
Quartz Geode Fragment
Silicon Dioxide (SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Granite (Pink/Potassium Feldspar Granite)
Felsic Plutonic Rock (Potassium Feldspar, Quartz, Mica, and Amphibole)
Sandstone
Arenite (SiO2 based with various cements)
Mica Schist
Mica Schist (KAl2(AlSi3O10)(OH)2 / K(Mg,Fe)3AlSi3O10(OH)2)
Granite (Weathered)
Course-grained Intrusive Igneous Rock