Whether your cat is a purebred russian blue or not we do not know because it is impossible to know about his pedegree but it looks pretty much lime one.
Read this.
http://www.petful.com/cat-breeds/russian-blue-cat-profile/
Whether your cat is a purebred RB, that we just wouldn't know because there's no way to know about his pedegree, although he looks like one.So this is a breed?
I do feel very lucky to have been picked by him. Oftentimes people talk about "trapping" stray cats and such. In my case, there was no trapping involved, he ran right into my house!
I do have to wonder if he was a lost pet though, especially since he was already neutered. However he had no collar and no microchip and our calling around and placing an ad drew no replies.
Read this.
http://www.petful.com/cat-breeds/russian-blue-cat-profile/