Can anyone tell me if this is a fossil?

[Tmackalaska]

I recently inherited my great uncles small fossil collection and rock collection. I spent a lot of time with him and can identify most of what I have because he loved to pull them out and show them to me throughout the years. But I have two that I have never seen before. I’m not sure if they are even fossils. I’ve been to a lot of museums and to dinosaur National park many times with him but I have never seen anything like either of these. Unfortunately, I don’t know where he got them. He traveled all over the world and spent much of his retired years traveling so I wouldn’t even be able to guess where they came from. I apologize for that. 
The first one is almost like a crystal. You can almost see through it but it has the pattern of reptile skin. The second one I took pictures of both sides and a close up of it because I don’t even know how to describe it. Any help you can give me would be appreciated. Thank you

[Ludwigia]

The first one is definitely some kind of crystalline mineral, perhaps calcite, in botroyoidal form on matrix. I'm not sure about the second one though and would defer to someone who knows better.

[Coco]

Agree with a mineral for the 1st. To know if it is calcite it would be necessary to see the broken side of the mineral to see the shape of the break.

 

You can also put white vinegar on the broken mineral. If it makes bubbles it is calcite.

 

Coco

Edited March 10 by Coco