The (in)visibility of lost wax casting moulds in the archaeological record: observations from an archaeological experiment

Abstract

Apart from mould and core remnants attached to metal objects from the Chalcolithic Southern Levant (ca. 4500–3800 BCE), production remains of early lost wax casting are seemingly invisible in the archaeological record. An experiment using reproduced casting moulds was performed to simulate the Chalcolithic processes to investigate whether the moulds might have deteriorated to an unrecognisable state after the casting process. Results from previous studies on mould remains attached to metal objects were complemented with ethnographical accounts for the experimental set-up. The moulds were prepared from local clays already in use during the Chalcolithic. Petrography, simple alteration tests, and general technological considerations reveal that preservation may be poor but is still visible to the naked eye. The preservation of multi-layered fragments is crucial, despite their friable or brittle state after casting. A further, previously unmentioned, clear indication of lost wax casting moulds may be the combination of vegetal temper with mineral/rock temper in their clay paste. This composition derives purely from technological considerations and is independent of depositional and post-depositional processes.

Identification of Fazael 2 (4000–3900 BCE) as first lost wax casting workshop in the Chalcolithic Southern Levant

“…11b), which is comparable to the unheated control sediments (Table 1). [32] suggest that ceramics in the Chalcolithic Southern Levant were most likely tempered according to their specific purposes based on the comparison of crucibles fragments, fragments of lost wax casting moulds attached to metal objects, and ceramic vessels. They came to the conclusion that pure chaff temper was exclusively used for metallurgical ceramics, a mix of chaff and mineral temper for lost wax casting moulds and pure mineral temper only for non-metallurgical pottery.…”

“…Following the concept of the purpose-specific temper choice [32], some baked sediment nodules may be fragments of lost wax casting moulds. Although the combination of mineral inclusions and vegetal temper was only observed in F2-YA3 (Fig.…”

“…F225a seems to be a fragment of a baked sediment nodule by its shape, but its clay paste is completely different from the other nodules' clay and the clay used for F225 and F229. Containing vegetal and mineral non-plastic inclusions, it would be placed into the lost wax casting mould category according to the concept of purpose-specific temper choice [32]. At the same time, it is the only nodule with some kind of smoothed surface.…”

Bellows and furnace covers in the unalloyed copper metallurgy of the Chalcolithic Southern Levant: reassessing the evidence from Abu Matar

“…A clay paste of Negev loess and carbonate sand is typical for domestic pottery of the Northern Negev, whereas Negev loess with vegetal temper was exclusively used for metallurgical ceramics (Rose et al, 2023; Shugar, 2000). Consequently, the petrographical and typological data indicate the secondary use of a V‐shaped bowl and a hole‐mouth jar in a metallurgical context.…”

Experimental Archaeogaming

“…Why would a crossdevelopment system be used? We can look to physical analogs to understand the reasoning, such as using clay to form molds for metal casting (Bruhns 1972;Rose et al 2023;Silas 2005), where working in one medium allows more ease and flexibility than another. If we extend this lens of ease and flexibility to the domain of computers, a cross-development system would be used when one or more of the following situations exist:…”