
Obsidian possibly used in trephination experiments
1918-1920
1918-1920
1771-1830
circa 2016
circa 2016
circa 2016
1992-1999
1701-1800
1790-1831
1501-1600
1992-1999
1901-1930
1851-1900
1915-1953
1981-1990
1875
1771-1830
1771-1830
1771-1830
1901-1930
1701-1800
1701-1800
1900-1992
1999-2001
1999-2001
1914-1918
2016
circa 2016
circa 2016
circa 2016
1998
2015
1880-1920
1900-1915
1970-1985
1980-1985
circa 2016
2000
1980-1990
1876-1900
1871-1930
1890-1910
2017
1771-1830
1771-1830
1771-1830
1771-1830
1601-1700
1701-1800