Our examination of over 230 worldwide opal samples shows that X-ray diffraction (XRD)
remains the best primary method for delineation and classification of opal-A, opal-CT and …

The Raman effect is at the basis of Raman scattering and microspectrometry: in the first part
of the chapter, it is very shortly exposed together with differences with infrared (IR) …

It was recently found that silcrete raw material was heat-treated during the South African
Middle Stone Age (MSA) for altering its flaking properties. This finding led to hypotheses …

SiC/SiC composites play a pivotal role in aerospace and energy applications for their
excellent resistance to high temperatures, corrosion, oxidation, and low density. This paper …

Siliceous rocks that were not heated to high temperatures during their geological formation
display improved knapping qualities when they are subjected to controlled heating …

In archaeology, heat treatment of stone is the process of “making” a new material for tool
production. Its invention in the African Middle Stone Age was an important step in the …

In archaeology, heat treatment is the process of intentionally modifying lithic raw materials to
improve their knapping quality. Even though the nature and parameters of the thermal …

A collection of Hellenistic–Roman glyptics, kept at the Regional Archaeological Museum
“Paolo Orsi”(Syracuse, Italy), was investigated in situ with portable Raman spectroscopy with …

Production of stone artefacts using pyro-technology is known from the Middle and Upper
Palaeolithic of Europe and the Levant, and the Middle Stone Age in Africa. However …

The quantitative determination of moganite in flint and chert plays an important role in the
characterisation of these silica rocks and in the study of their genesis and evolution. Both …