I clean my fossils with normal soap and water using a toothbrush. But this time i think i broke a piece of a really Nice crinoid stem. Either that or im just overthinking like i have done before. But the question is what matrix is Good for cleaning and whats not. The crinoid was not in any matrix. There was a mix of shale and limestone there. I know shale is not good to clean with water. I got some horn corals that are kinda muddy. No matrix but it wont easily get off the fossil. Well after the crinoid im not sure if i should use soap and water. What other things can i use? Anyways heres the crinoid. And how can u know a old damage from erosion or a fresh damage? Sorry for all the questions and long text