Humåtak, Guam, USA
Apophyllite crystals growing with natrolite crystals. Specimen in the collection of the Smithsonian Institute, Washington DC. USA. Scale at bottom of specimen is an inch with a rule at one cm.
© Rock Currier
Analcime crystals. From the collection of the Smithsonian Institute. Scale at bottom of image is an inch with a rule at one cm.