Very cool rock and strange.If I was to hazard a guess I would think it was found in an area that has hot springs in the area and the white is some type of mineral that pushed up through the sedimentary sandstone.Just a guess.
I thought this might be some type of fossil, found several unusual rocks or , plus many great examples of petrified wood. The property had been owned by a rock hound, he passed away, the property was sold and plowed up, the pictured rock is one of many unusual items.
Thanks for the replies