Works of "Research Collection"
Place Collected: Limberg Quarry #1
Place Collected: Auvergne
Place Collected: Eifel Mtns.
Place Collected: open pit, 76 m level
Place Collected: open pit, 60-67 m level
Place Collected: open pit
Place Collected: open pit, 50-60 m level
Place Collected: open pit, 60-67 m level
Place Collected: open pit, 60-67 m level
Place Collected: open pit, 67 m level
Place Collected: Val D' Ossola