Anatase
Single metallic X , 1.3cm long.
Anatase is one of the forms of titanium dioxide found in nature, the other are rutile and brookite; the three minerals have the same chemistry (TiO2), but different structure.
XX of anatase are very distinctive, they form the eight faced tetragonal bipyramids that come to elongated points and this elongation distinguish this form from octahedral XX
6.5x5cm
Valdres Valley, Valdres, Oppland. Norway
Specimen n.671