Sandstone (likely Quartzose type)
Clastic sedimentary rock (primarily SiO2)
Category
Browse man made object (coin) specimens identified by the Rock Identifier community.
Sandstone (likely Quartzose type)
Clastic sedimentary rock (primarily SiO2)
Sandstone (with Iron Staining)
Clastic Sedimentary Rock (primarily SiO2 with FeO(OH) impurities)
Rose Quartz with Schist Matrix
Silicon Dioxide (SiO2) with Mica-Schist
Feldspar (Orthoclase)
Potassium Feldspar (KAlSi3O8)
Basalt with Olivine inclusion
Mafic Volcanic Basalt (Fe,Mg)2SiO4
Potassium Feldspar (Orthoclase)
KAlSi3O8 (Potassium Aluminum Silicate)
Sandstone
Arenite (SiO2 primarily)
Sandstone (specifically Red Sandstone)
Arenite (primarily Quartz, SiO2)
Ironstone Concretion (Limonite/Goethite)
Ferruginous Sandstone or Limonite (FeO(OH)·nH2O)
Red Jasper
Silicon dioxide (SiO2) with iron oxide inclusions
Biotite Schist
Biotite Gneiss/Schist (approximate formula K(Mg,Fe)3AlSi3O10(OH)2)
Ironstone (possibly Bog Iron or Limonite)
Goethite-rich Ironstone (FeO(OH))
Jasper with Iron Staining
Silicon Dioxide (SiO2) with Hematite impurities
Greenstone / Epidosite
Epidosite (Metasomatic rock consisting mainly of Epidite Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH) and Quartz)
Obsidian
Obsidian (Volcanic Glass)
Quartzite
Quartzite (chiefly SiO2)
Turquoise
Turquoise (CuAl6(PO4)4(OH)8·4H2O)
Jasper (Iron-stained Quartz)
Silicon dioxide (SiO2) with iron oxide inclusions
Red Jasper
Silicon Dioxide (SiO2) with Iron inclusions
Jasper (Iron Oxide Rich)
Silicon Dioxide (SiO2) with Fe2O3 (Hematite/Goethite) inclusions
Green Fluorite
Calcium Fluoride (CaF2)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Fluorite (Purple variety)
Calcium Fluoride (CaF2)
Scoria
Vesicular Basaltic Glass
Veined Quartz
SiO2 (Silicon Dioxide)
Gneiss
Gneiss (High-grade Regional Metamorphic Rock)
Black Onyx
Silicon Dioxide (SiO2) with parallel banding
Milky Quartz
Silicon Dioxide (SiO2)
Basalt
Basalt (Mafic Extrusive Igneous Rock)
Chert (concretionary/nodular variant)
Microcrystalline Quartz (SiO2) with possible fossil or mineral inclusions
Zebra Jasper
Jasper (variety of Quartz/Chalcedony), SiO2
Schist
Mica Schist (primarily consisting of muscovite, biotite, and quartz)
Oolitic Limestone
Oolite (Sedimentary Calcium Carbonate)
Red Sandstone
Arenite (Ferruginous Sandstone)
Rose Quartz
Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese
Obsidian
Volcanic Glass (predominantly SiO2)
Limestone
Calcium Carbonate (CaCO3)
Peridot
Olivine (specifically, the gem-quality variety forsterite, (Mg,Fe)2SiO4)
Serpentinite (often containing Jadeite/Nephrite)
Antigorite-rich Serpentine Rock, (Mg, Fe)3Si2O5(OH)4
Quartzite
Quartzite (SiO2)
Moqui Marble (Shaman Stone)
Ironstone Concretion (Fe2O3 with a sandstone core)
Granodiorite
Granodiorite (Intermediate intrusive igneous rock)