Nuummite

Nuumite Information, from wikipedia.com
 * < Category || Mineral Variety ||
 * < Formula || (Mg2) ||
 * < (repeating unit) || (Mg5)Si8O22(OH)2 ||
 * < Formula mass || 780.82gm ||
 * < Color || Black,Grey ||
 * < Twinning || None ||
 * < Cleavage || Perfect on 210 ||
 * < Fracture || Conchoidal ||
 * < Mohs scale || 5,5-6.0 ||
 * < hardness ||  ||
 * < Luster || Vitreous/glossy ||
 * < Diaphaneity || opaque ||
 * < Density || 2.85-3.57 ||
 * < Refractive Index || 1.598-1.697 ||