Crushed Rock Metals
2020-11-6ensp0183enspCrushed Stone, Gemstones, and Minerals from CrushedGems. Blue Metal 5, 10, 20mm Blue Metal is a quarried, crushed aggregate rock that can range in colour from blue to black. It comes in three sizes 5 mm, 10 mm or 20 mm, and is primarily used in making concrete. Because it is a clean, crushed rock, it is also ideal.