this is something I’d been wondering about for about a year. To take a piece of salvaged stone and use what would normally be discarded as waste for a sculpture. In this instance I had a large block of Portland stone salvaged from the Blackfriars Bridge regeneration project. We used the bulk of the stone for a student project (gothic tracery rounded window) and I set the off cut aside rather than chuck it in the skip. It’s covered in cementicious mortar that would have bonded it to the next stone. It was approx 2 m long coming from an original block of 2/2/1 metres that would’ve weighed around 3 tonnes.  Having been part of a bridge for around 100 years the stone increases  in hardness  and with the cement was difficult to work with. My original idea was to use the entire 2m length for one sculpture but as I assessed it on the saw table it occurred to me to use half and maybe a pair. Looking at the pattern of the cement, the absence of cement, the staining and the tool marks, inc the original masons mark (crudely carved as proof of who made it and who therefore should be paid for it),and the ratios and proportions that hinted at form, I judged the long and short cuts to be made on the table saw. then I took one half , drew on the cut out based on one third of width and used a 9″angle grinder to cut the lengths and a 5 ” on the widths. However, while the 9 cuts the depth the 5 could only part cut the depth of the width so I had to stitch drill the length and chisel one end free. Using a lump hammer to pop out the cut out in one hit was very enjoyable. The rest of the job was hard work. Drilling, chiselling, filing, riffling and hand rubbing. Final high pressure wash. Very pleased. Took home, photographed, delivered to client next day. They loved it