Meteorite is a dial material made by cutting a meteorite into thin slices, then polishing each slice flat and etching it with acid. The acid brings out the contrast between the metal crystals, which makes their pattern visible. That pattern formed as molten metal cooled extremely slowly in space.
What is the Widmanstätten pattern?
On iron meteorites, the pattern is made of interlocking bands of two iron-nickel alloys. Kamacite is low in nickel. Taenite is high in nickel. The bands formed because molten metal cooled extremely slowly in space. The pattern is named after Count Alois von Beckh Widmanstätten. The name was given by Carl von Schreibers of the Vienna Mineral and Zoology Cabinet. It is also called a Thomson structure, after William Thomson. In 1804 he revealed the pattern by treating a meteorite with nitric acid.
Where it comes from
The first meteorite dial is said to have appeared on a Corum Admiral in 1986. Its material came from the Cape York meteorite in Greenland. Rolex was the first large brand to bring meteorite dials into the mainstream. It took its dial material from the Gibeon meteorite. Most meteorite dials are cut from Gibeon or from Hoba. Both meteorites come from Namibia. John Herschel recognised Gibeon as a meteorite in 1836. Since 1950 it has been protected as a Namibian National Monument.
How hard is meteorite, and can it be coloured?
Meteorite is fairly soft. It measures 4 to 6 on the Mohs hardness scale. This sets it apart from most gemstone dials, which are harder. The surface can also be changed after cutting. Etching with acid makes the crystal pattern visible, and heat treatment can add colour. Blue, purple, orange and yellow are all possible. So the same meteorite can give dials in quite different shades.
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