Technology and Terminology of Knapped Stone - IRIT

5.3. Alteration s
Frost pits,
(i
pot lid" fractures and their complements
Whatever its origin, thermal damage is shown by concentric direction lines (fig. 50).
Crazing
Frost damage or heat-altering (intentional or unintentional) causes, crazing to develop on
the surface of the object; the network of fine cracks is depicted by a lattice of short broken lines.
Patina and heat treatment
Changes in the texture, colour or sheen of some patinated or heat-treated artefacts may
occur (fig. 1 : 7). This difference between original and altered state is figured by drawing two
illustrations of the same view. The first drawing shows the original aspect of the artefact, the
second portrays only the altered zones. On each of the two drawings the zones that are not
emphasized are finely hatched.
When artefacts bear multiple patinas, the same view is repeatedly drawn to show each
of the successive patinas.
5.4. Addition s
As studies on additions (ochre, bitumen, etc.) are relatively recent, no conventional
method of portrayal has yet been devised. They are drawn in a figurative way or indicated by
fine grade shading film (fig. 51). Ochre-bearing artefacts are best rendered by the use of colour.
Fig. 51 — Proximal fragment of a Canaanean blade bearing traces of gloss (stippled shading film and
dotted line) and bitumen (small areas of black flat tint), flint, Kutan, Iraq (Anderson, Inizan,
1994 : fig. 3).
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