Commemorative Tie Clip

This item was likely given to participants in a Ministry of International Trade and Industry (MITI, at the time) research and development project for jet engine development, approximately 50 years ago.
I received it from someone. It is a non-commercial item and extremely rare.
The material is unknown. It appears to be gold-plated.
It has been stored in a drawer for nearly 50 years, so there is some minor soiling (?).
There are no scratches.
No claims accepted.