Human Skin (Epidermis/Dermis)
Integumentary tissue (High content of hydroxyapatite in bones, though the surface is biological)
Mineral-like biological tissue
Category
Sedimentary Or Igneous (Secondary Formation)
Browse sedimentary or igneous (secondary formation) specimens identified by the Rock Identifier community.
Rose Quartz (or Quartzite)
Silicon Dioxide (SiO2)
mineral
Pearl
Organic gemstone (Calcium carbonate / CaCO3 + Conchiolin)
mineral
Siltstone/Sandstone (possibly Wonderstone or Picture Sandstone)
Clastic Sedimentary Rock (primarily SiO2 with Iron Oxide inclusions)
Sedimentary
Chert (Flint)
SiO2 (predominantly microcrystalline or cryptocrystalline quartz)
Sedimentary rock
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
mineral
Pink Banded Agate (Dyed)
Chalcedony (cryptocrystalline silica), chemical formula SiO2
mineral
Rose Quartz
Quartz (SiO2) with trace elements of titanium, iron, or manganese
mineral
Basalt
Mafic Volcanic Rock (Primarily Plagioclase and Pyroxene)
Igneous
Gneiss
Gneiss (High-grade Metamorphic Rock)
metamorphic
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Grey Limestone Pebble
Limestone (Calcium Carbonate - CaCO3)
sedimentary
Dolomite
Dolomite (CaMg(CO3)2)
Mineral
Pearl
Biogenic CaCO3 (Aragonite)
mineral
Quartz (Milky/Rose Quartz variety)
Silicon Dioxide (SiO2)
mineral
Fluorite
Calcium Fluoride (CaF2)
mineral
Quartz (Common or Milky)
Silicon Dioxide (SiO2)
mineral
Quartz Geode Fragment
Silicon Dioxide (SiO2)
mineral
Pyrite
Iron Sulfide (FeS2)
mineral
Quartz Geode
Silicon Dioxide (SiO2)
mineral
Fluorite
Fluoride (Calcium Fluoride - CaF2)
mineral
Blue Calcite
Calcium Carbonate (CaCO3)
mineral
Yellow Calcite
Calcium Carbonate (CaCO3)
mineral
Fluorite
Calcium Fluoride (CaF2)
mineral
Clear Quartz
Silicon Dioxide (SiO2)
mineral
Quartz (Milky/Crystalline variety)
Silicon Dioxide (SiO2)
mineral
Quartz (Milky/Clear variety)
Silicon Dioxide (SiO2)
mineral
Clear Quartz
Silicon Dioxide (SiO2)
mineral
Clear Quartz Crystal
Silicon Dioxide (SiO2)
mineral
Graphite
Graphite (Native Carbon), Formula: C
Metamorphic
Gneiss
Gneiss (Metamorphic rock composed primarily of quartz, feldspar, and mica)
metamorphic
Pyrite (Iron Pyrites)
Iron Sulfide (FeS2)
mineral
Optical Calcite (Iceland Spar)
Calcite (Calcium Carbonate, CaCO3)
mineral
Quartz (Milky or White Quartz)
Silicon Dioxide (SiO2)
mineral
Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
mineral
Chalcedony (Quartz Var.)
Silicon Dioxide (SiO2)
mineral
Pyrite
Iron Sulfide (FeS2)
mineral
Pyrite
Iron Disulfide (FeS2)
mineral
Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
mineral
Quartz (Milky Quartz / Quartzite)
Silicon Dioxide (SiO2)
mineral
Yellow Aventurine
Quartz (Silicon Dioxide - SiO2) with inclusions of Mica
Mineral
Azurite and Malachite on Matrix
Cu3(CO3)2(OH)2 (Azurite) and Cu2CO3(OH)2 (Malachite)
mineral