Consider the following statements about Harappan craft production:
1. Chanhudaro was a specialised urban centre devoted almost exclusively to craft production.
2. Steatite beads were shaped by moulding a paste made from powdered steatite.
3. Carnelian beads acquired their red colour through polishing and exposure to sun.
4. Tools and waste materials are key indicators of production sites for archaeologists.
Which of the above statements is/are correct?