This... phallus.. found near some Kaibab limestone and shell

what is this? got it for a friend and forgot what it was 😭the

I found this on the shoreline of Lake Michigan while I was rock

Any ideas what this could be?

Citrine? Or baked amethyst? Either way I love the rainbows inside

Any idea what this is?

Found this beauty. Help identify please? 🙏