Dutrowite

The first tourmaline group member with essential titanium. The Fe²⁺-analogue of magnesio-dutrowite. Unique combination of elements at time of naming. A Mg-dominant analogue, probably magnesio-dutrowite, is reported from Zlatá Idka, Slovakia (Bačík et al., 2022). Most likely a late-stage phase resulting from replacement of "biotite" during a late-magmatic/hydrothermal event at high temperature but low pressure.