HELP WANTED Heaven’s Light our Guide

I am showing this little 20mm flat button because I would appreciate any helpful suggestions about its origin and who might have worn it. It is well made but has no maker’s mark on the back. I assume it has some connection with the Order of the Star of India. I have not attempted to clean it but wonder what metal it is. Where it has been a little rubbed on the high points of the lettering and on the star it looks as though it could be silver.