Home / Explore / Minerals / Heidornite Minerals Heidornite heidornite Na2Ca3B5O8(SO4)2Cl(OH)2 Heidornite mineral information and data — via www.dakotamatrix.com · Source Overview Heidornite is a mineral species (borate mineral). It crystallises in the monoclinic system. Nickel–Strunz class: 6.EC.30. Scientific references Heidornite — Wikidata. https://www.wikidata.org/wiki/Q3784124 Link