I've had several requests to know what I used for the floors in The Citadel, so I'm going to tell you what I used and how to get it.
I get the "Petrified Wood" pattern from Formica.com It comes in 12x12" samples. No two samples are the same which makes for great varied colors.
On the web site it's under their 180 FX grouping. Note: they will only send one sample per request so, if you need more, you may want to wait a couple of days then request another. They will ship the sample at no charge.
Then I just use my Proxxon table saw to cut the sample into 1" wide strips then into random lengths.
Then I just glue it down. I try to mix up the colors to give it a more varied look.