>>13806130Well it certainly looks like a seam of gold, not so much on the other picture though, could be bad lighting and it's further away. Does it run on the sides too? The texture on the bottom right on the first image is also quite interesting. Could be just nothing as well, even if it was gold it wouldn't be worth much unless it's bigger on the inside. It does look bit tarnished on the second image so it could just be fools gold.
Since it's not crystaline you could easily do some destructive testing, break it in half and see if the seam continues, maybe take some close up images and look for the typical cubic/angular formations of pyrite, you could measure the weight and see if it's heavy. Hit it with a needle or small knife and see if it breaks or just mushes together or gets sliced in 2 or hit it with a file and see if the dust is still gold colored.
Or you know just leave it as it is, the first side at least looks pretty cool.
