Limonite after Pyrite (Prophecy Stone)
Limonite (FeO(OH)·nH2O) replacing Pyrite (FeS2)
Mineral pseudomorph
Category
Mineral (Processed Alloy)
Browse mineral (processed alloy) specimens identified by the Rock Identifier community.
Yellow Jasper
Silicon Dioxide (SiO2) with Iron inclusions
sedimentary
Quartz Vein in Host Rock (Pebble)
Quartz (SiO2) with sandstone or siltstone matrix
metamorphic/igneous transition
Serpentine
Serpentine Group Minerals (e.g., Antigorite, Chrysotile, Lizardite)
Mineral, often found as a rock
Amethyst (Rough Quartz)
Silicon Dioxide (SiO2) with iron impurities
mineral
Serpentinite
Serpentinite (complex silicate minerals including lizardite, chrysotile, and antigorite: (Mg,Fe)3Si2O5(OH)4)
metamorphic
Greenschist
Greenschist (chlorite-epidote schist)
metamorphic
Beads (likely glass or man-made material)
N/A (artificial material)
Man-made material, not a natural rock or mineral specimen
Serpentinite
Serpentinite (complex silicate minerals including Mg3Si2O5(OH)4)
metamorphic
Quartz Vein in Host Rock
Silicon Dioxide (SiO2)
mineral
Ferruginous Quartz
Silicon Dioxide (SiO2) with Hematite/Limonite impurities
mineral
Red Jasper
Silicon Dioxide (SiO2) with Hematite impurities
mineral
Quartz (specifically Citrine or Yellow Quartzite pebble)
Silicon Dioxide (SiO2)
mineral
Yellow Quartz (Citrine/Quartzite Pebble)
Silicon Dioxide (SiO2)
mineral
Watermelon Tourmaline
Elbaite - Na(Li1.5Al1.5)Al6(Si6O18)(BO3)3(OH)3OH
mineral
Tourmaline (Schorl or Dravite) on Matrix
Complex Borosilicate - Na(Mg,Fe,Li,Al,Mn)3Al6(BO3)3Si6O18(OH,F)4
mineral
Citrine Quartz
Citrine (Silicon Dioxide, SiO2)
mineral
Orange Calcite
Calcium Carbonate (CaCO3)
mineral
River Quartz
Quartz (Silicon Dioxide, SiO2)
mineral
Petrified Wood (Jet or Coalified Wood appearance)
Silicified wood (principally SiO2) or Carbonized Wood
sedimentary
Larimar
Pectolite (Sodium Calcium Silicate Hydroxide) - (NaCa2(Si3O8)(OH))
Mineral
Tiger's Eye (Polished Point/Tower)
SiO2 (Silicon Dioxide) with included crocidolite fibers
Mineral (Metamorphic pseudomorph)
Tiger's Eye (Rough)
Pseudomorph of Quartz after Crocidolite (SiO2 with iron inclusions)
metamorphic
Serpentinite
Serpentinite (composed primarily of minerals in the Serpentine group: Chrysotile, Lizardite, and Antigorite)
metamorphic
Precious Opal
Hydrated amorphous silica (SiO2·nH2O)
mineral
Engineered Quartz Stone
Agglomerated Quartz (SiO2 + Polymer Resin)
mineral-based composite
Granite
Granite (a plutonic igneous rock composed of quartz, feldspar, and mica)
igneous
Petrified Wood (Silicified Wood)
Silicified Wood (primarily Chalcedony/Quartz, SiO2)
mineral
Blue Calcite
Calcium Carbonate (CaCO3)
mineral
Blue Calcite
Calcium Carbonate (CaCO3)
mineral
Quartz Druzy on Matrix (likely Agate or Jasper)
Silicon Dioxide (SiO2) with various mineral inclusions
mineral
Amethyst
SiO2 (Silicon Dioxide with Iron impurities)
mineral
Orange Calcite
Calcium Carbonate (CaCO3)
mineral
Orbicular Jasper (Ocean Jasper)
Silicon Dioxide (SiO2) with iron and magnesium inclusions
mineral
Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
mineral
Jasper with Quartz Veining
Silicon Dioxide (SiO2) - Cryptocrystalline Chalcedony
sedimentary
Banded Sandstone
Arenite (composed primarily of Quartz: SiO2)
sedimentary
Serpentinite
Serpentinite (composed primarily of Serpentine group minerals: (Mg,Fe)3Si2O5(OH)4)
metamorphic
Shale (sub-type: Carbonaceous Shale)
Lutaceous Sedimentary Rock
sedimentary
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Mahogany Obsidian
Volcanic Glass (Silicate: SiO2 + Fe2O3)
igneous
Petrified Wood
Silicified wood (primarily SiO2)
sedimentary