I have made some Live rock from agatized coral I have found in a Special location i have in North Central Florida. The Coral is Millions of Years old and I had to Dig it out of the Creek bank.
1. I washed it off.
2. Lightly Bleached it (to get the Dirt Stains Out)
3. Rinsed it and soaked it in Fresh water for a week then Rinsed it again.
4 After that I placed the Rocks in 5 gallon buckets and Put my Used water changed water in the Buckets for about 6 weeks (every Water change I would change out the water in the rock buckets).
The Rocks took to the Tank Like champs. I even sold some to a Fish shop,
I will Post some Pics of the Coral. It's Really cool and looks great in the tank.