Sedimentary (Secondary Mineral Formation)

Browse sedimentary (secondary mineral formation) specimens identified by the Rock Identifier community.

Sandstone

Arenite

sedimentary

Amethyst

Amethyst (Silicon Dioxide, SiO2)

mineral

Tiger's Eye (specifically Blue/Golden mixed or Hawk's Eye)

Pseudomorph of Quartz after Crocidolite (SiO2)

metamorphic

Iron Slag

Iron/Steel Slag (Ferrosilicate Glass)

industrial byproduct (anthropogenic material)

Granite

Granite (Mainly Quartz, Feldspar, and Mica)

igneous

Red Jasper

Silicon dioxide (SiO2) with iron oxide (Fe2O3) inclusions

sedimentary

Lepidolite

K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2 (Lithium-bearing Mica)

mineral

Tiger's Eye (Inlaid in a band)

SiO2 (Silicon Dioxide with Crocidolite inclusions)

mineral

Milky Quartz (with potential inclusion of feldspar)

Silicon Dioxide (SiO2)

Mineral

Chalcedony (Agatized Coral / Rough Chalcedony Node)

Silicon Dioxide (SiO2)

mineral

Rose Quartz

Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese

mineral

Milky Quartz

Silicon Dioxide (SiO2)

mineral

Chert (or Flint)

Chert (microcrystalline or cryptocrystalline quartz, SiO2)

Sedimentary

Rhodonite

Manganese Inosilicate (MnSiO3), often with Ca, Fe, Mg, Zn

Mineral

Green Tourmaline (Verdelite)

Tourmaline Group; often Elbaite (Na(Li,Al)3Al6(BO3)3Si6O18(OH)4) or Dravite (NaMg3Al6(BO3)3Si6O18(OH)4)

Mineral

Granodiorite with Biotite Mica

Granodiorite (containing Quartz, Plagioclase Feldspar, and Biotite Mica)

igneous

Petoskey Stone

Hexagonaria percarinata (Fossilized Coral)

sedimentary

Pumice

Pumice (volcanic rock)

Igneous

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

mineral

Amazonite

Amazonite (KAlSi3O8, a variety of Microcline)

Mineral

Argetine Blue Agate (Chalcendony variant)

Silicon Dioxide (SiO₂)

mineral

Tiger's Eye

Pseudomorph of Quartz after Crocidolite (SiO2)

mineral

Tiger's Eye

Pseudomorph of Quartz after Crocidolite (SiO2)

metamorphic

Tiger's Eye

Pseudomorph of quartz after crocidolite (SiO2)

metamorphic

Milky Quartz

Silicon Dioxide (SiO2)

mineral

Rhodonite

Rhodonite; (Mn,Fe,Mg,Ca)SiO3

Mineral

Aquamarine

Beryl (Be3Al2Si6O18 with iron traces)

mineral

Granite

Phaneritic Igneous Rock (composed of Quartz, Feldspar, and Mica)

igneous

Thunderegg (Agate-filled Geode Node)

Silicon dioxide (SiO2) with various inclusions

sedimentary/igneous association

Synthetic Resin / Plastic Figurine

Synthetic Polymer (Copolymer of Polyethylene or Resin)

Mineraloid-like Synthetic Material

Garnet (likely Pyrope or Almandine)

Garnet Group (complex nesosilicate minerals, e.g., Pyrope Mg3Al2(SiO4)3, Almandine Fe3Al2(SiO4)3, Spessartine Mn3Al2(SiO4)3, Grossular Ca3Al2(SiO4)3, Andradite Ca3Fe2(SiO4)3, Uvarovite Ca3Cr2(SiO4)3). The vivid red color in the image strongly suggests Pyrope or Almandine.

Mineral

Ametrine

SiO2 (silicon dioxide)

Mineral

Banded Metamorphic Rock (likely Quartzite or Serpentinite/Soapstone)

Metamorphic Rock (possibly a banded Quartzite or a foliated Serpentinite/Talc Schist based on appearance, general term for such a rock is 'Banded Metamorphic Rock' or 'Gneiss' if pronounced banding of different minerals)

Metamorphic