Bonaccordite is a rare mineral discovered in 1974. Its chemical formula is Ni₂FeBO₅ and it is a mineral of the ludwigite group. It usually crystallizes in long, cylindrical prisms that form within another source. It is named after the area of Bon Accord, where it was first found. There have also been findings of bonaccordite within nuclear plants at multiple companies. It builds up a deposit within the machines and is a very hard mineral to clean out because it is resistant to ordinary techniques.