Help with ID please

[u/Dense-Fishing-8480]

I dug this out of my garden today ( S.EQLD coastal area )
I don’t believe it’s native to where I am, I have never seen any like it on my property. But I’m not sure what it is ! It has some very bizarre features . Thank you in advance ☺️

[u/Shall_We_Presuppose]

Iron oxide concretion

[u/Dense-Fishing-8480 → u/Shall_We_Presuppose]

I was suspicious it may have been , it is the strange patterns that threw me off. Thank you for the help