Using tufa as a building material ?

I can't tell you ladies and gentlemen how excited I am to find this forum and to learn about making stuff with tufa. I have yet to make up some but plan to start small later this week.

Our yard is about two acres, some level and some hilly. I have a bunch of idea's for building stuff with tufa and the first project is a garden wall, sort of a retaining wall but short, say two feet max by about 10 feet long.

I have three or four big blocks of styrofoam salvaged from a boat dock that I think would make great molds for making tufa stones. Dig out holes or forms in the foam, pack them full of tufa and let it cure. The holes could be customized into different sizes, thickness's, shapes, etc. The back sides would be smooth, or all the sides except the front which would make them easy to work with, just like brick. I want to experiment with different color additives and sprinkle some with iron oxide so they have these rust streaks down them. The possibilities are endless !!!

I would also like to make bigger blocks, the sizes of regular concrete blocks or even larger and by digging holes in the ground I would like to make different sized boulders for landscaping. These blocks will only have to support their own weight depending on how high I stack them, not for a building foundation or stuff like that.

So, what do you think ? Will tufa stand up to the heat and winter rain of Oklahoma ? I guess if they crack or weather that would only add to their old apparence. I've learned a lot just from reading the tufa threads and can't wait to get started.

Des