dry rock question

[jonh5150]

I bought some dry rock ( Marco Key Largo) to re-do or finish my 75 gal. I want to use the bigger pieces in a pillar style. Does anyone have any experience cutting a flat spot on these rocks. Would a plane ol hack saw fit the bill? this is one I likedView attachment 9761

 

[Top Water]

Would not use a power plane but a hacksaw with a metal cutting blade might work but a diamond blade saw would work best