Alois von Beckh-Widmanstätten
The Viennese scientist whose name was given to the criss-cross crystal pattern seen inside iron meteorites.
Key facts
- Born
- 1754
- Died
- 1849
- Nationality
- Austrian
- Field
- Scientist and printer
Count Alois von Beckh-Widmanstätten trained as a printer in his family's business before working in Vienna as a scientist in imperial service. He was interested in materials and how they behave when heated.
In 1808 he took a polished slice of the Hraschina iron, which had been seen to fall near Zagreb in 1751, and heated it gently in a flame. The different metals in the slice tarnished to different colours, and a striking pattern appeared: long, interlocking bands crossing one another at set angles, like a lattice. Widmanstätten did not publish his discovery himself, but he showed it to colleagues, and the Vienna curator Carl von Schreibers later printed images of etched irons, inked and pressed directly onto paper.
The pattern is made of two nickel-iron alloys. Kamacite, with little nickel, forms broad plates. Taenite, richer in nickel, forms thin ribbons between them. They separate only when metal cools extremely slowly, a few degrees every million years, deep inside an asteroid. No iron made on Earth shows the same coarse pattern, so it is one of the surest signs that a piece of iron is a meteorite.
An Englishman, William Thomson, had in fact seen the pattern four years earlier in Naples, and some scientists call it the Thomson structure. But the name Widmanstätten pattern is the one used around the world.
Did you know?
Prints made by inking an etched iron slice and pressing it onto paper were among the first nature prints in science.
The pattern is revealed today by etching with a weak acid, which only adults should do with proper safety equipment.
On the timeline
- 26 May 1751Hraschina: two irons fall near Zagreb
- 1808Widmanstätten heats the Hraschina iron
- 1820Meteorites print their own pictures