Franz Eugen Hussak, Austrian-born Brazilian mineralogist and petrographer (Wilden, Steiermark 10 March 1856 – Poços de Caldas, Minas Gerais State 05 September 1911)

First described the pseudoleucites (1890)

Presented first accurate reports about microstructure of titaniferous iron ores

DESCRIBED NEW MINERAL SPECIES

Gorceixite (1906)

Zirkelite (1895) with Prior

Senaite (1898) with Prior

Lewisite (1895)

Derbylite (1895) with Prior

Tripuhyite (1897) with Prior

Florencite (1899) with Prior