Hello! Please help me identify this mineral. The nearest I found (so far) is "rounded white prehnite," but it doesn't seem like it. I found this years ago at a river here in the Philippines and it's only now that I'm feeling curious again to know what this is called. Thank you for your time!
n.b. (1) The black specks on the white substance are just dust from years being stacked away (2) Please click the image to go to Photobucket if you'd like to zoom in on it.