Technology of Gonjos-Separate Piece of Early Indonesian Daggers (Keris)

摘要

The technology of making of the Gonjos (separate part of Indonesian Keris) was not known up to date. First of these iron (belonging to Pajajaran, Tuban, Majapahit-Madere, 13~(th)-16~(th) A.D.), were examined in the Foundry Research Institute in Krakow (Poland) specializing in metallographic examinations or early irons too. One examined Gonjo (No. 6) was forged of iron with low concentration of this admixture, two others (Nos. 2 and 8) of iron with higher content of phosphorus (0.19 and .031 percent) with "Band Structure". Four Gonjos (Nos. 3-5 and 7) were joined of numerous thin layers of selected grades of iron with low and high phosphorus content. Thanks special arrangements of these layers arose characteristic Indonesian pattern on the surface of Gonjos (and Keris). The phosphorus content in thin layesr of iron was estimated using distinguish phosphorus and arsenic. Thus some irons identified using this reagent as phosphorous may contain arsenic.One Gonjo (No. 1) was made of hard Indian steel ("Wootz"), but with slightly lower carbon content (0.8-1.3 percent C) than necessary for making famous Damascene blades.