I was given a bunch of 3/4" solid walnut flooring left over from a large estate flooring installation. It's t&g in 7", 5" and 3" widths and unfinished. Can it be used for exterior decking?

I'd like to use it as a small landing (4'x8') outside a new art studio. I'd install it on a standard 2"x6" raised subdeck on piers.

Before I start, any comments from someone who has used Walnut as an exterior deck?

Thanks,