Pyrite
Iron Disulfide (FeS2)
Category
Browse sedimentary or igneous (host environment) specimens identified by the Rock Identifier community.
Pyrite
Iron Disulfide (FeS2)
Hematite
Iron(III) oxide (Fe2O3)
Quartz Vein in Host Rock
Silicon Dioxide (SiO2)
Pebble or Cobble (likely composed of sandstone or conglomerate)
Clastic Sedimentary Rock (specific name like sandstone, conglomerate, or breccia would require microscopic analysis of clast size and angularity)
Rainbow Fluorite
Calcium Fluoride (CaF2)
White Quartz Pebble
Silicon Dioxide (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Black River Stone (Chert or Basalt Pebble)
Microcrystalline Quartz (SiO2) or Mafic Igneous Rock
Quartz
Quartz (SiO₂ - Silicon Dioxide)
Milky Quartz in Gneiss
Quartzite / Foliated Gneiss containing SiO2
Limonite with Opal infusion
FeO(OH)·nH2O (Limonite) / SiO2·nH2O (Opal)
Shale or Slate with Quartz Veins
Shale (fine-grained clastic sedimentary rock) or Slate (low-grade metamorphic rock formed from shale) with Quartz (SiO2) veins
Black Obsidian and Hematite
Volcanic Glass (SiO2) and Hematite (Fe2O3)
Milky Quartz
Silicon Dioxide (SiO2)
Agate
Silicon Dioxide (SiO2) - Banded Chalcedony
Serpentinite
Serpentinite (complex of lizardite, chrysotile, and antigorite: (Mg,Fe)3Si2O5(OH)4)
Fossiliferous Shale or Slate with Plant Fossils
Fossil-bearing argillaceous rock
Quartz Druzy on Agate (River Cobble)
Silicon Dioxide (SiO2)
Arkosic Sandstone
Arkose
Quartz (River Pebble)
Quartz (SiO₂ - Silicon Dioxide)
Black Tourmaline
Schorl (NaFe3Al6(BO3)3Si6O18(OH)4)
Gold Nugget (or Gold Grain)
Native Gold (Au)
Quartz Druze
Silicon Dioxide (SiO2)
Lapis Lazuli
Complex metamorphic rock containing Lazurite ((Na,Ca)8(AlSiO4)6(SO4,S,Cl)2), Calcite, and Pyrite
Banded Agate (Agate Slice)
Silicon Dioxide (SiO2) - Variety of Chalcedony
Banded Agate (Crazy Lace/Mexican Agate Variety)
Silicon Dioxide (SiO2)
Schist with Quartz Vein
Mica Schist with Crystalline Quartz (SiO2)
Rose Quartz
Quartz (Silicon Dioxide - SiO2) with trace amounts of titanium, iron, or manganese
Blue Chalcedony
Silicon Dioxide (SiO2)
Sandstone (Red)
Arenite (primarily Quartz, SiO2, with Iron Oxide cement)
Quartz in Matrix (possibly Basalt or Siltstone host)
Silicon Dioxide (SiO2) in Host Rock
Celadonite in Basalt (Green Earth)
Celadonite (K(Mg,Fe2+)(Fe3+,Al)Si4O10(OH)2)
White Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
Raw Emerald
Beryl (Be3Al2Si6O18 with Chromium/Vanadium impurities)
Carnelian
Carnelian (a variety of Chalcedony, which is a microcrystalline quartz, SiO2)
Red Siltstone (or Red Shale)
Clastic Sedimentary Rock (Composition: primarily Quartz, Clay minerals, and Hematite Fe2O3)
Chrysocolla in Jasper (Chryso-Jasper)
Cu2-xAlx(H2-xSi2O5)(OH)4·n H2O (Chrysocolla) + SiO2 (Jasper)
Turquoise in Matrix
CuAl6(PO4)4(OH)8·4H2O (Hydrous phosphate of copper and aluminium)
Boulder Opal
Hydrated Silica (SiO2·nH2O)
Basalt with Caliche Crust
Aphanitic Mafic Igneous Rock with Calcium Carbonate (CaCO3) coating
Agate (Water-Worn Pebble)
Silicon Dioxide (SiO2) - Chalcedony
Quartz
Silicon Dioxide (SiO2)