SPARE PARTS

Square section facilitates the ashlar collocation while building walls up. As two of their three dimensions keep always the same, each stone allows diverse optimal positions and stone rows formation is a bit easier.
Hardness of these stones is adequate to allow modellers adjust to the limit each single stone to the adjacent ones with some sand paper.   
Pieces length is variable. Approximately 5% of the pieces measures 5.5 mm, 10 %  of the stones are 7.5 mm long, 5% are around 12 mm, and the rest of pieces, most of them, measures around 10 mm length.