I was looking through some of the rocks I have collected over the years and came across this one, appears to be an ordinary rock but with a strange fracture, it doesn’t look like a rock that would hold a fossil and the shape doesn’t remind me of anything which is why I’m pretty sure it is just a crack in the rock but I thought it odd that it was symmetric, since I am not 100% sure it’s a rock I thought I’d ask here scale is in mm, about 5 mm long
first image shows the whole rock
2nd image shows another view of the rock
3rd image shows the fracture with scale
4th shows fracture from a different angle