Health in Senior Cats

I have a cat who is almost 9 years old and sometimes she has a habit of peeing on the floor but what bothers me is that when her pee dries it is all crystally around the edges could someone tell me why her pee is like that ? Thank you

The crystal stuff is mostly salt and other toxins that are eliminated by the cat. I have 5 cats currently and when they pee on something hard, like a wooden floor, the dried remains usually looks crystallized, especially around the outer edges.  This is normal AFAIK.

Jim 

Have you tried to figure out why she's not using the box?  That's a red flag for me.