The Chamleon Blocks mod for 1.7.2 adds blocks to the game that can take the form of any block/item. This lets you create traps, stack any items, or make whole diamond structures with just one diamond.
Usage:Place a Chameleon block on the side of a normal block and it will instantly fade to recreate the block you placed it next to. You can then place another Chameleon block on the first one and it will also fade! When you break the normal “master block” the two Chameleon blocks will switch to their own color again.
First located the minecraft folder by pressing the windows key and going to “Run”.
Type in %appdata%
Location .Minecraft folder, open this and locate the “Mods” folder