“Bright white Humberstonite on translucent Nitratine, 2cm by 2.3cm. Former Jaroslav Hyrsl collection. Rolf Luetcke specimen and photo.”

“Bright white humberstonite with nitratine, not visible in this close up. Former Jaroslav Hyrsl collection. Rolf Luetcke specimen and photo.”

“Colorless nitratine, close up with minor amounts of white humberstonite. Former Jaroslav Hyrsl collection. Rolf Luetcke specimen and photo.”