Is this really petrified dino dung?

Question

Going through my old rock collection from when i was young.  My grandmother gave me this and told me it was petrified dino poop.  Is that true?  If not, what is it?

Answer 1

The whitish part with reddish veins looks like quartz.

The darker part is hard to tell, could be almost any rock.

Answer 2

Does not look like it. You can google coprolite and see if what you have matches what you will see. Feces is made up of a pile of small particles of undigested food and is more like sandstone. Yours looks like a chunk of solid rock.