Help! What is it and where can I get it? Hit it with a hammer?

[mousiemousie]

You hit it with a hammer and there might be a fossil inside...from dd's xmas present list...what are these called and where can I get them from??!!!

HELP!

I know there are ones with crystals in called volcanic geodes from Hawkins Bazaar. Not sure about fossils.

Geodes - also sold in NT shops - DS got one

(& was most disappointed - I think he thought there would be a diamond insdie!)

OH YOU ARE ALL WONDERFUL

thank you