The unusual Cali glass from Colombia is of volcanic origin, according to latest research. (A. Crosta/Newsflash)
Researchers Prove Humboldts 200 Year Old Claim About Volcanic Origin Of Cali Glass Was Right
New research has proved that Alexander von Humboldt was right in a claim he made 200 years ago about the volcanic origin of the so-called 'Cali glass'. The Cali glass…