Did you have to sandblast previously installed stone or the stone you did?

I did the whole feature wall, had it almost complete and the customer decided that they did not want the color we had originally decided upon. I tried to color over it but decided that that would not work out in the long run and Butterfield is costly. So I decided to rent a bigger compressor than what I had, I had a small sandblaster that I had purchased on a whim to try on my stone at some time for testing out different types of effects. The hopper on the gun was really small, enough for 3 cups of #70 silica, so my bro thought to take the hopper off of my GFRC gun and attach it to the sandblaster. Great idea, it now held a gallon before it got to heavy to hold. This worked great and took about 4 hrs to complete the feature wall, it was than ready to recieve stain again. BTW a small hand held sandblaster is a really cool way to get some great looks before or after staining.