Subject ASC000113o
The Quarterly journal of the Geological Society of London.
v.56 (1900), Page 510 (1900)
Smithsonian Libraries
BHL Page 41487880
Keywords
rock New Zealand obsidian glass inclusions hornblende feldspar perlitic obsidian devitrified spherulitic obsidian felsite polarized light spherulitic rhyolite pumice-tuff rhyolite hyalite microscopic view vulcanic rocks spherulites geology new zealand rocks New Zealand Rocks