
Obsidian possibly used in trephination experiments
1918-1920
1918-1920
circa 2016
circa 2016
circa 2016
1501-1600
1801-1900
1920-1930
1901-1930
1880-1920
1900-1915
1914-1918
2016
2015
1875
1771-1830
1980-1985
1771-1830
1771-1830
1998
1992-1999
2000
1851-1900
1915-1953
1701-1800
1771-1830
1999-2001
1999-2001
circa 2016
circa 2016
circa 2016
circa 2016
1981-1990
circa 2016
circa 2016
circa 2016
1601-1700
1771-1830
1771-1830
1771-1830
1771-1830
1970-1985
1998
1998
1992-1999
2017
1980-1990
1958-1960
1850-1910
1740-1840