Hi Steve
Is your discriminator turned all the way down? If so then it must be gem material of some kind for you can see the crystal structures in it.
Is the crystalline structure hard, does it refract light or just reflect it?
Looks like a paste broach that was melted, but those could be real gems too.
If it is iron pyrite here is some info:
Pyrite is an iron sulfide generated by sulphur reacting with iron present in sedimentary rock (limestone & sandstone) in a reducing environment. It comes in an astonishing array of forms -- from discoids (also known as sunflowers), to suns, to perfect cubes -- all in the same glittering, glassy, golden shade. When found with quartz crystals (as it often is), the encrustation of pyrite causes the quartz to form delicate, needle-like points unlike any you've seen before! Pyrite is also part of what makes Lapis Lazuli (a vivid blue rock with pyrite veins) such a popular stone for tumbling, beads, and carving.
let us know what you find and thanks for sharing
Sanat