strengths and weaknesses, to produce a more accurate composition of the sam-
ple. Elemental maps may also be generated from EDS or WDS data. Figure 8
compares dot mapping with regular SEM images for inclusions in glass.
3.3 Dating Methods
The dating of an object is critical both from an archaeological point of view
and from a museum point of view. In the first case, it will allow a date to be
attributed to a settlement, or provide a chronological sequence in an excav-
ation. In the second case, it may confirm or refute the assigned provenance of
the object. Unfortunately, there is no single dating technique applicable to all
materials. For example, obsidian objects can be dated by the thickness of the
hydration layer that forms on this volcanic glass once an object has been
fashioned out of it. Wood can often be dated by dendrochronology, which
Methods in Conservation 23
Figure 8SEM and dot mapping of inclusions in glass