This is the famous Hindsgavl Dagger.
The following is an excerpt of the FlintForum digest, from Mike Stafford
who is the curator of Anthropology, Cranbrook Institute of Science in
"The dagger was found at Hindsgavl, Denmark, a town on the south-central island of Fyn.
To my eye it is the most impressive stone tool made anywhere, anytime.
But I'm also biased towards the Danish stuff.
This dagger is actually close to 12" long and is
unbelievably wide. The blade is finished in massive pressure flakes
over a ground surface. The reddish color is from bog patination over
translucent Danish flint. Chronologically this dagger dates to near
1900 BC. It is technically classified as a type IVe in the dagger
typology established by Lomborg.
This dagger, considered a Danish national treasure, is on permanent
display in the Danish National Museum in Copenhagen".