Collection
Classification: IIIAB Iron
Observed fall: No
Year found: 1968
City, Country: Saint-Aubin, France
Mass: 472 kg
In collection
Weight #1 : 75 g
Weight #2 : g (1968 mass)
Certificate of authenticity: Yes (2)
The Saint-Aubin meteorite is a notable example of a IIIAB iron meteorite, discovered in northern France. Classified within the largest chemical group of iron meteorites, it consists predominantly of iron-nickel alloys—kamacite and taenite—that crystallized from a slowly cooling metallic core of a differentiated asteroid. When polished and etched, Saint-Aubin displays classic Widmanstätten patterns, showcasing its intricate internal structure and extraordinarily slow cooling history over millions of years. This meteorite also contains inclusions of sulfide and phosphide minerals, revealing complex chemical processes that occurred deep within its parent body. Studying Saint-Aubin provides valuable clues to the formation, differentiation, and long-term thermal evolution of early planetary building blocks in our solar system.
When examining a polished and etched section of the Saint-Aubin IIIAB iron meteorite under a reflected light microscope, you primarily observe the classic Widmanstätten patterns, formed by intersecting lamellae of kamacite and taenite. These lamellae appear as distinct, geometric bands with varying brightness due to differences in their nickel content and reflectivity. In addition, you may spot small schreibersite (iron-nickel phosphide) inclusions and occasionally troilite (iron sulfide) nodules as darker, opaque areas. Fine lines known as Neumann lines may also be present within the kamacite, indicating shock deformation. Overall, the microscopic view provides a remarkable glimpse into the slow cooling and complex internal structure that shaped this iron meteorite.
