Sandstone (Ferruginous)
Arenite (variable SiO2 with Fe2O3 staining)
Category
Browse man made byproduct (often mistaken for obsidian or emerald) specimens identified by the Rock Identifier community.
Sandstone (Ferruginous)
Arenite (variable SiO2 with Fe2O3 staining)
Quartzite
Quartzite (SiO2)
Serpentine
Serpentine Group (Mg,Fe,Ni,Al,Zn,Mn)2-3(Si,Al,Fe)2O5(OH)4
Ferruginous Sandstone
Arenite with Iron-oxide cement (composed of Quartz and Limonite/Hematite)
Fluorite
Calcium Fluoride (CaF2)
United States Quarter Dollar
Cupronickel Clad Alloy (75% Copper, 25% Nickel over a 100% Copper core)
Pink Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
Jasper with Hematite inclusions
Silicon Dioxide (SiO2) with Fe2O3
Azurite
Azurite (Cu3(CO3)2(OH)2)
Milky Quartz
Silicon Dioxide (SiO2)
Eclogite
Eclogite (Omphacite-Garnet rock)
Clay (as a rock-forming material)
Clay minerals (e.g., Kaolinite group, Smectite group, Illite group, Chlorite group)
Verde Antique Marble (Serpentinite)
Serpentinite (composed mainly of Serpentine group minerals, Mg3Si2O5(OH)4)
Green Calcite
Calcium Carbonate (CaCO3)
Chert (Cherty Limestone / Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Sandstone (Quartz Sandstone)
Arenite (primarily SiO2)
Quartzite
Quartzite (SiO2)
Sandstone (Ferruginous)
Clastic Sedimentary Rock (SiO2 with Fe2O3/FeOOH cement)
Orpiment
Orpiment (As2S3)
Chalk (Sedimentary Pebble)
Calcium Carbonate (CaCO3) - Biogenic Limestone
Olivine in Basalt (Peridot)
Magnesium Iron Silicate (Mg, Fe)2SiO4 in Vesicular Basalt
Serpentinite
Serpentinite (complex silicate minerals including Mg3Si2O5(OH)4)
Quartzite
Quartzite (SiO2)
Quartz (Milky Quartz / Greenish Quartz)
SiO2 (Silicon Dioxide)
Citrine
Silicon Dioxide (SiO2) with iron impurities
Quartz / Chert
Silicon Dioxide (SiO2)
Orange Calcite
Calcite (Calcium Carbonate, CaCO3)
Ironstone Concretion
Siderite or Hematite Concretion
Limonitic Iron Ore / Goethite
Hydrated Iron(III) oxide-hydroxide (primarily FeO(OH)·nH2O)
Sodalite
Sodalite (Na8(Al6Si6O24)Cl2)
Yellow Jade (Nephrite or Quartzite variety)
Ca2(Mg,Fe)5Si8O22(OH)2 (Nephrite) / SiO2 (Quartzite variant)
Quartzite
Quartzite (SiO2)
Picture Jasper
Silicon Dioxide (SiO2) with iron oxide and clay inclusions
Jasper
Silicon Dioxide (SiO2)
Amber
Succinate (Fossilized Tree Resin)
Milky Quartz with Matrix
Quartz (Silicon Dioxide, SiO2)
Yellow Quartz (Citrine or Iron-stained Quartz)
Silicon Dioxide (SiO2)
Milky Quartz (Water-Worn Pebble)
Quartz (Silicon Dioxide, SiO2)
Lava Rock (Scoria)
Scoria (highly vesicular basaltic rock)
Quartz / Rock Crystal
Silicon Dioxide (SiO2)
Yellow Calcite
Calcium Carbonate (CaCO3)
Clear Quartz Point
Silicon Dioxide (SiO2)