Ichthyosaur Fossil
Image: <a href="//commons.wikimedia.org/wiki/User:Archaeodontosaurus" title="User:Archaeodontosaurus">Didier Descouens</a> (CC BY-SA 4.0)
Mineral NameIchthyosaur Fossil
Chemical FormulaFeS2 (for pyritized fossil material)
Mohs Hardness6
Lustermetallic
Streak ColorGreenish-black
CleavageIndistinct
FractureConchoidal to uneven
Specific Gravity4.95
Colorsdark metallic bronze, gold, black, dark gray
Transparencyopaque
Type LocalityHolzmaden, Germany
Mineral GroupFossil (material primarily Sulfide, e.g., Pyrite)
Usesscientific study, museum display, collector's item
Associated MineralsHarpoceras falcifer (ammonite fossil), Dactylioceras (ammonite fossil), clay minerals (in matrix), calcite (in matrix), quartz (in matrix)
Rarityrare
Description
A well-preserved skeleton of a marine reptile, Temnodontosaurus acutirostris, with a metallic sheen, embedded in a dark gray shale matrix, surrounded by several golden ammonite fossils.
Geological Context
This fossil dates back to the Lower Jurassic (Toarcian) period, approximately 185 million years ago, and was formed in the anoxic marine environments of Holzmaden, Germany, leading to exceptional pyritized preservation within black shales.
