Works of "Research Collection"
Place Collected: Klein Spitzkoppe
Place Collected: 30 km W of Borzya
Place Collected: Swinna Ness
Place Collected: Niederhovels near Wissen am der Sieg
Place Collected: 2 km W of Kragero
Place Collected: Nikka North Quarry
Place Collected: Hollersbachtal
Place Collected: Campo Tencia