
Obsidian possibly used in trephination experiments
1918-1920
1918-1920
1918
1952-3
1830 (original); 1967 (model)
circa 1919
1919
1917
1920
1668; 1924
1610; 1923
1920
1918
1921
1917
1918
1921
circa 1920
1955; 1830
1918
1921
2000-100 BCE
1917-1918
circa 1920
1920
1934
1903 (original); 1982 (model)
1772 (original); 1919 (model)
1917-1918
circa 1917
1930 (replica); 1834 (original)
1919
1839 (original); circa 1988 (replica)
circa 1920
1801-1892 (prepared); 1946 (element replaced)
1918
1921
circa 1920
1920
1920
1920
1990-96
1917
1918-1920
4000-2001 BCE
1934
1990-95
1919
circa 1930; 1920
1918 - 2000
1730-1760 (original); 1931-1939 (replica)