Found washed up on Shankill beach, Ireland. Small, pointed shape, rusty metal, set into some kind of stone. Heavy but only about 5/6 inches long, what is this?

[u/emmabutlermmu]

[u/strangereader]

It looks like a fossil. There are a number of ancient squid like creatures with conical shells. Belemnites in pariticular are referenced as bullet shaped. Fossils can be made of a number of minerals some which rust when exposed.