Limestone
Calcium Carbonate (CaCO3)
Category
Browse man made byproduct (often mistaken for obsidian or emerald) specimens identified by the Rock Identifier community.
Limestone
Calcium Carbonate (CaCO3)
Quartzite with Hematite staining
Quartzite (SiO2)
Bull Quartz (Milky Quartz)
Quartz (Silicon Dioxide - SiO2)
Celestite (Celectine)
Strontium sulfate (SrSO4)
Quartz (Variety: Rose Quartz/Smoky Quartz mix)
Silicon Dioxide (SiO2)
Basalt (Water-worn Pebble)
Basalt (Aphanitic Mafic Igneous Rock)
Agate (Moss or Plume Agate variety)
Silicon Dioxide (SiO2)
Rhodonite
Manganese Inosilicate (MnSiO3)
Quartzite
Quartzite (primarily SiO2)
Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
Rough Diamond
Native Carbon (C)
Oolitic Ironstone
Sedimentary Ooidal Ironstone (Limonite/Hematite mixture)
Serpentinite
Serpentinite (composed primarily of mineral group (Mg, Fe, Ni, Al, Zn, Mn)2-3(Si, Al, Fe)2O5(OH)4)
Sandstone
Arenite
Rough Diamond
Native Carbon (C)
Green Fluorite (Beaded)
Fluorite (Calcium Fluoride, CaF2)
Quartzite
Quartzite (primarily SiO2)
Pegmatite with Smoky Quartz and Feldspar
Pegmatite (Quartz: SiO2, Feldspar: KAlSi3O8)
Jasper with Hematite inclusions
Silicon Dioxide (SiO2) with Iron Oxide (Fe2O3)
Green Fluorite (likely synthetic or heat-treated for jewelry)
Calcium Fluoride (CaF2)
Chert (specifically a flint nodule component)
Microcrystalline quartz (SiO2)
Fluorite (Purple variety)
Calcium Fluoride (CaF2)
Quartzite
Quartzite (primarily SiO2)
Quartzite Pebble
Quartzite (primarily SiO2)
Stichtite in Serpentine (Atlantisite)
Mg6Cr2CO3(OH)16·4H2O (Stichtite) within Mg3Si2O5(OH)4 (Serpentine)
White Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
Chert (Black Chert/Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Ocean Jasper
Orbicular Jasper (Silicon Dioxide, SiO2)
Red Mudstone (Siltstone)
Lutite (primarily Quartz and Clay minerals with Hematite)
Jasper
Silicon dioxide (SiO2)
Map Jasper (Grey Picasso Jasper)
Silicon Dioxide (SiO2) with impurities
Sandstone (Wonderstone)
Silicified Sandstone / Orthoquartzite with Liesegang rings
Quartzite
Quartzite (primarily SiO2)
Chert (specifically Flint or Gray Chert)
Silicon Dioxide (SiO2)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Chert / Flint (with quartz or calcite inclusion)
Silicon dioxide (SiO2)
Greywacke
Greywacke (Lithofeldspathic Sandstone)
Strawberry Quartz
Silicon Dioxide (SiO2) with Hematite or Goethite inclusions
Milky Quartz
Quartz (Silicon Dioxide - SiO2)
Orange Quartzite (Tumble-polished)
Quartzite (primarily SiO2)
Quartzite
Quartzite (SiO2)
Olivine in Basalt (Peridotite Xenolith)
Forsterite-rich Olivine (Mg2SiO4) in Aphanitic Basalt