That suggests these rocks have been near a molten iron core.

BBC: A fleeting encounter with an 'inbetweener'

Unlike any other asteroid known today, Vesta has an iron core surrounded by layers of mantle rock and crust, similar to Earth and Mars, preliminary gravity and density measurements suggest.

WSJ: Asteroid Vesta Gets a Close Study

The magnetometer will record what, if any, magnetic field the asteroid has, thus revealing whether it was ever part of an object large enough to have possessed the molten iron core needed to generate such a field.

ECONOMIST: An erotic encounter

The inner core, made of very pure, solid iron, rotates along with the outer core, dragging the Earth's magnetic field with them.

BBC: Earth's wobbles reveal deep secrets

Japanese researchers say the basalt in NWA 011 suggests the body from which it did originate had a core of molten iron with an outer covering of silicon and aluminium that formed a basaltic crust.

BBC: Mercury meteorite puzzle

The mining group has said that it wants to focus on core businesses such as iron ore and coal.

BBC: BHP Billiton sells Arizona copper mine to Capstone

The origin of this effect may lie at the boundary between the mantle, made up of viscous rock that extends 2, 900 km (1, 800 miles) below the crust, and the outer core, which is thought to be liquid iron with the consistency of water.

BBC: Earth's wobbles reveal deep secrets

Specifically, what the scientists have found is that the iron adopts a crystalline structure, like a diamond, in the Earth's core.

BBC: Planet Earth