Crossing the Borders: New Methods and Techniques in the Study of Archaeological Materials from the Caribbean

Investigating Stone Bead Drilling Techniques / 81
bead, and a drilled tablet, as well as an experimentally drilled calcite tablet, are discussed
here.
Methods
As it is not possible to directly view manufacturing traces on the inside walls of the
bore of intact beads, it is necessary to replicate the bores in order to examine them.
Although our efforts at obtaining high quality replicas to date have been met with
some challenges, we have been able to reproduce fine detail satisfactorily.
Initially, it was chosen to make molds of the bore with Resilpom Putty, a
silicone- based putty, for its qualities of gentleness toward archaeological specimens,
rapid curing time, and its ability to produce detailed replicas of an object.
Previously (De Mille and Varney 2003), we noted some challenges in producing
perfect molds with this putty. As such we consulted with a dental technologist
whose expertise in reproducing fine detail for various types of dental prosthetics
provided invaluable insights and new directions in seeking the optimal replication
materials and techniques. This led to the use of a new molding material, Elite
HD+ (manufactured by Zhermack), designed for creating high precision dental
impressions. This light- bodied two- component silicon is available in a variety of
colors, setting times, and consistencies. The “light bodied normal setting” form
was utilized as it has a viscous yet fluid consistency and is prepackaged in a cartridge
delivery device such that air bubbles are not introduced into the mold. It has
the added advantage of being a medium blue color, which serves to enhance observing
and imaging the relief on the mold.
In order to create a replica of the bead bores, the impression material was injected
into the bore. When it was set (15–20 minutes), it was removed from the bore
and placed into a “bowl” that was custom made to size using a fast- setting silicone
putty. This container served to hold the mold securely in place as well as contain
the liquid casting material in place until it set. This technique was adopted after
some experimentation so that only half of the mold was cast at one time for intact
beads, allowing us to create a cast that did not need to first be sawn in half in
order to be viewed. The casting material was prepared using a mechanical mixer
under vacuum that eliminated any air bubbles in the casts that were produced.
Casts produce a more permanent and positive replica of the bead bores; however,
our attempts at casting have not yet produced satisfactory results due to difficulties
in capturing adequate images of the three- dimensional detail that exists on
the casts. The best results were achieved using a museum grade casting material,
Aqua- Resin, and we will next try coating the casts with a thin coating of carbon or
metal before viewing under the microscopes to enhance imaging.
It was decided upon to use scanning electron microscopy due to its exceptional
capability for observing fine topographical detail. Recent advances in SEM tech-
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