Marble
Recrystallized Calcite (CaCO3)
Category
Browse man made object (coin) specimens identified by the Rock Identifier community.
Marble
Recrystallized Calcite (CaCO3)
Fluorite
Fluorite (Calcium Fluoride, CaF2)
Rose Quartz
Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese
Unakite
Unakite (Metasomatized Granite)
Marble
Recrystallized Calcite (CaCO3) Rock
Shiva Lingam
Cryptocrystalline Quartz (Jasproid/Chalcedony mix)
Gold
Native Gold (Au)
Sandstone (Ferruginous)
Arenite (primarily SiO2 with Fe2O3 staining)
Basalt
Basalt (Mafic volcanic rock)
Sandstone
Clastic sedimentary rock (primarily SiO2)
Yellow Quartz / Citrine Quartz
Silicon Dioxide (SiO2)
Scoria (Red Lava Rock)
Scoria (Vesicular Basalt/Andesite)
Clear Quartz (or Rock Crystal)
Quartz (SiO₂)
Green Fluorite
Fluorite (Calcium Fluoride - CaF2)
Garnet-bearing Schist
Almandine Garnet (Fe3Al2(SiO4)3) in Mica Schist
Quartz Veined Rock (Likely Graywacke or Quartzite)
Silicon Dioxide (SiO2) veins in Metasedimentary matrix
Citrine (likely Heat-Treated Amethyst)
Silicon Dioxide (SiO2)
Coquina
Coquina (a type of limestone)
Breciated Red Jasper
Silicon Dioxide (SiO2) with Hematite inclusions
Zebra Jasper
Tumbled Opaque Chalcedony (SiO2)
Jasper
Chert (Silica: SiO2)
Sandstone (likely Siltstone or Mudstone variety)
Clastic Sedimentary Rock (primarily SiO2 with iron oxides)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Quartz (Milky/Clear variety)
Silicon Dioxide (SiO2)
Sapphire (likely blue synthetic sapphire or blue glass in a ring)
Corundum (Al₂O₃), specifically the blue variety due to trace amounts of iron and titanium impurities. If synthetic, it would still be Al₂O₃.
Red Sandstone
Clastic sedimentary rock (primarily SiO2 with Fe2O3)
Sandstone (Ferruginous)
Sandstone (Clastic sedimentary rock, predominantly SiO2 with Fe2O3 cement)
Sandstone
Arenite (primarily SiO2)
Crushed Limestone
Calcium Carbonate (CaCO3)
Sandstone
Arenite
Fossiliferous Limestone
Biogenic Calcium Carbonate (CaCO3)
Granite (Weathered)
Phaneritic Felsic Igneous Rock
Serpentinite
Serpentinite (composed primarily of serpentine group minerals like lizardite, antigorite, and chrysotile)
Limestone
Calcium Carbonate (CaCO3)
Iron-Nickel Meteorite (Possible Chondrite or Oxidized Iron)
Siderite (Nickel-Iron) or Chondrite (Si/Fe composite)
Basalt (Vesicular)
Extrusive mafic igneous rock; primarily (Mg, Fe)2SiO4 (Olivine), CaAl2Si2O8 (Plagioclase Feldspar), and Pyroxene
Quartz Geode Fragment
Silicon Dioxide (SiO2)
Red Jasper
Silicon Dioxide (SiO2) with Hematite (Fe2O3) inclusions
Pink Satin Spar (Satin Spar Selenite Dyed)
Gypsum (CaSO4·2H2O)
Rough Green Fluorite
Fluorite (Calcium Fluoride - CaF2)
Red Jasper
Silicon Dioxide (SiO2) - Microcrystalline Quartz with iron inclusions
Red Jasper (nodule)
Silicon Dioxide (SiO2) with Iron Oxide inclusions