Minerals in space group 55

Ludwigite is a magnesium-iron borate mineral: Mg2FeBO5.

Nenadkevichite is a rare silicate mineral containing niobium with the chemical formula . It forms brown to yellow to rose colored orthorhombic dipyramidal crystals with a dull to earthy luster. It has a Mohs hardness of 5 and a specific gravity of 2.86.

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.

Eugenite is a rare silver-mercury mineral. It crystallizes in the orthorhombic crystal system.

thumb | right Stumpflite is a rare platinum mineral. It crystallizes in the orthorhombic crystal system.

Reinerite is a rare arsenite (arsenate(III)) mineral with chemical formula Zn3(AsO3)2. It crystallizes in the orthorhombic crystal system.