A truly refractory crucible from fourth millennium Tepe Hissar, Northeast Iran

From the Early Chalcolithic to the Late Iron Age, melting and smelting crucibles were usually made from non-refractory ceramic fabrics, which required heating of the charge from within the crucible to avoid collapsing the ceramic itself. In this paper, an unusual melting crucible from Northeast Iran, radiocarbon-dated to the Late Chalcolithic (ca. 3600 BCE), will be presented that significantly changes our understanding of the development of technical ceramics in Southwest Asia. This crucible, made of a highly refractory talc-based ceramic held together by an outer layer of traditional non-refractory ceramic, is to our knowledge unprecedented at such an early date. As will be argued, this ancient crucible was heated from the exterior or from below and not from the interior. This method of firing, combined with the highly-specialized construction technique, makes this crucible so far unique in prehistoric metallurgy, and forces us to re-examine traditional models for the development of technical ceramics and metallurgical practices in the Old World.     

Technology,chronology and the role of crucible steel as inferred from iron objects of the ancient site at Junnar,India

Ordinary iron objects from an ancient habitation site at Junnar in India, dating to the 2nd BC to AD 2nd century, were examined for their microstructure, chemical composition and age. The objects were mostly made of high carbon steel with a homogeneous microstructure consisting of fine spherical particles of carbide in the ferrite background, free of non-metallic inclusions. Their carbon concentration ranged from 0.7% to over 1.6% with one exception at 0.2%. Some of them contained trace amounts of silicon, manganese and sulfur while one object retained cavities due to volume contraction during solidification reactions. These features indicate that the objects examined constitute an early example of Indian steel making in crucibles. Evidence was found that basic techniques needed for the success of crucible steel technology were mostly available at Junnar at the time. The radiocarbon measurement on carbon samples extracted from one of the iron objects placed its date between 176 BC and AD 20, in agreement with the radiocarbon dates of three charcoal samples from the same site. The forgoing results support that crucible steel was produced in India at a much earlier date than previously supposed, to serve as a material for specific needs arising in daily life.     

重庆彭水徐家坝遗址出土商周时期的船形杯功能研究

2009年,重庆彭水徐家坝遗址出土了一件船形杯,其用途到底是什么?学术界一直未有一个定论。本工作利用检测手段,从物质成分和结构方面揭示出徐家坝遗址出土船形杯的用途。扫描电镜能谱分析显示船形杯体中含有大量的Cu和Pb以及微量的Sn,杯体表层分离出来的铜块为Cu、Sn和Pb三元合金的铸造组织结构。同时,杯体表面青灰色残留物的X-射线衍射分析显示其中含有锡石(SnO2)、氧化铜(CuO)和碳(C)。实验数据表明巴人在商周时期已经了解到了青铜合金的性质,掌握了青铜冶铸技术,有力证实船形杯可以作为冶铸工具坩埚的观点。