This is an Iron age cist burial containing both a sword and a bronze mirror. Very unusual for a burial to contain both these objects. The burial itself is devoid of any skeletal remains, the soil here is too acid. A cornish friend of mine knows the farmer who found the sword while ploughing, and I have a copy of a dvd of the excavation but don't know how to take the photos from it.
Both the sword and the mirror can be seen in the Scilly Isles museum.