One of our long-term aims is a detailed study of Oriental Arms & Armour in the Wallace Collection, London (which has over one thousand items, and is the most important collection of Indian arms and armour outside the subcontinent). These are swords, helmets and shields of princely quality, and it is important that any analyses are non-invasive. From 2009 we have measured at ISIS selected samples of Indian blades from Hyderabad and other private collections in order to determine their phase distribution by neutron diffraction.We have found that by neutron diffraction we can identify crucible steels by their high cementite content. Their hardness is generally due to unusually high carbon contents. However, there is a subclass within crucible steels of wootz (the so-called ¿Damascus steel¿). These are swords which had a visible pattern (resembling ¿watered silk¿) on the surface.