Official meteorite name: TW 500
Fallen: circa 200 000 years ago
Found: 6 May 2017
174 g
6.5 × 4.2 × 2.5 cm

Provenance:
Private collection, Switzerland

About 200 000 years ago, a tremendous spectacle must have taken place in the sky above Twannberg and the adjacent Jura mountains, as large chunks of iron rained down on the Earth. Today it is considered certain that the original asteroid measured 13–65 ft (4–20 m) in diameter before it exploded, and weighed at least 250 tons (113 000 kg).

The Twannberg strewn field, together with those in Morasko (Poland) or Muonionalusta (northern Sweden), is one of the largest and most important iron strewn fields in Europe. In Switzerland the Twannberg meteorite is the largest of eight known meteorites and the only one from which several fragments are known. Twannberg belongs to one of the rarest classes within the group of iron meteorites. Only six specimens of this iron meteorite type, which is characterised by a very low nickel content and a high phosphorus content, exist worldwide.

In May 1984, the farmer’s wife Margrit Christen found a conspicuously heavy stone while plowing a field, and with it the first fragment of the Twannberg meteorite. This discovery sparked a veritable ‘Twannberg treasure hunt’ in the following years.

The piece presented here is of very fine quality. Its graceful shape, its size as well as the stability and consistency of the iron (many Twannberg meteorites are in rather poor condition and badly rusted, after 200 000 years in the ground) make this item a reminder of the most important Swiss meteorite find of all time.