Meteorite Pallasit Brahin – Belarus

The Brahin meteorite is classified as a pallasite, which is a type of stony-iron meteorite. It was first discovered in 1810 in an area near the town of Brahin, located in Belarus. The meteorite's fall field measures approximately 15 kilometres in length and 3 kilometres in width and is crossed by the Dnieper River. The discovery was made by local residents who found metal fragments weighing 80 and 20 kilograms. The first samples were subsequently handed over to scientists who identified them as meteorite material. Subsequent discoveries of larger fragments of the Brahin meteorite were reported during the 19th and 20th centuries, with the largest pieces weighing up to several hundred kilograms. The total estimated weight of the fragments found is approximately 823 kilograms.

Structure

Pallasites are characterised by containing both metallic and silicate components in roughly equal proportions.

• Metallic component: consists mainly of iron and nickel. The metal matrix is made up of the main alloys:
• Taenite is a nickel-rich alloy (35-50 % Ni) and is characterised by its high hardness and silvery shiny appearance.
• Kamacite is an iron-rich alloy (typically 90-95% Fe) with a lower nickel content (5-10% Ni) compared to taenite. This alloy typically has a silvery grey colour and a metallic lustre. In meteorites it often forms broad bands that are easily visible on cutting surfaces. Kamacite is softer than taenite and together with taenite forms the basic structural component of the metallic phase of iron-nickel meteorites.
• Olivines: minerals composed mainly of forsterite and fayalite. Olivines in the Brahin meteorite are often large, clear and beautifully translucent, which adds to their aesthetic value. They are typically green to brownish in color and their quality is high, making them suitable for jewellery making.

Origin

The Brahin meteorite, like other pallasites, is interpreted as a fragment of an object that formed in the transition zone between the core and mantle of differentiated planetesimals. Planetesimals are small bodies that formed early in the Solar System, some of which may have given rise to later planets. Pallasites, including the Brahin meteorite, are thought to be fragments of these planetesimals that underwent a differentiation process that separated the metallic core from the silicate mantle.