Chromite

Chromite is an ore that contains the mineral “chrome”, used to make colourfast dyes and paints.

In the 19th Century chrome was recognised as a useful mordant for wool dyeing and for leather tanning. It was widely used to make the colour “Chrome Green” for artists and is still in use today. Chromite was mined at Dun Mountain in Nelson and shipped over to the United Kingdom, for use mainly in cotton dyeing. The London-registered Dun Mountain Copper Mining Company Ltd was formed to exploit this resource but the costs were too high and the venture was never a huge success. However, a visit from the geologist, Dr Ferdinand von Hochstetter, at the request of the Nelson Provincial Government resulted in a new name for a type of rock that contained flecks of chromate of iron. Noticing that the rock was unusual, he called it Dunite after the mountain, and the name has become international.

Incidentally, there are other rocks that were first described from the country and their names are also international. Rodingite and ignimbrite are found elsewhere but goodletite is only known from Aotearoa. For more about rocks and minerals in New Zealand follow this link.

The Nelson Museum has a wedding dress that is believed to have been dyed with local chromite. The photograph above (courtesy of the Nelson Provincial Museum) is on display because the actual item is in storage due to its fragility. Martha Thompson wore this green silk wedding dress at her marriage to James Rutherford on 28 April 1866 in Spring Grove, Nelson. Martha was mother of Ernest, Lord Rutherford, the world’s first alchemist and splitter of the atom. In a neat turn of events, Lord Rutherford is the only New Zealander who has an element (and a mineral) named after him: rutherfordium (and rutherfordine).