Ancient glass trade

Complications arise from the fact that for long periods of time glass was made following very similar recipes and as such the major elements found do not vary significantly.

However, as scientific techniques improve it is becoming increasingly possible to discern some compositional groups, together with other archaeological and textual evidence a picture of glass technology, industry and exchange is starting to emerge.

It was a material for high-status objects with archaeological evidence for the Late Bronze Age (LBA) also showing an almost exclusive distribution of glass finds at palace complexes such as that found in the city of Amarna, Egypt.

[2] At the first two sites cylindrical ceramic vessels with vitrified remains have been identified as glass crucibles,[3][4] where the raw materials (quartz pebbles and plant ash) would be melted together with a colourant.

The two sites seem to show a specialisation in colour, with blue glass, via the addition of cobalt, being produced at Amarna and red, through copper, at Pi-Ramesses.

Further supporting this hypothesis are the Amarna Letters, a contemporaneous diplomatic correspondence detailing the demand and gift giving from vassal princes in Syro-Palestine to the Egyptian king; in these the most requested item is glass.

The major element composition of glass finds from Mesopotamia and Egypt is indistinguishable, with as much variation found within a specific assemblage as between different sites.

As analytical techniques develop the presence of trace elements can be more accurately determined, and it has been found that glass is compositionally identical within each region, but it is possible to discriminate between them[clarification needed].

That there was a large scale and centralised production even this early is evidenced by the Ouest Embiez I shipwreck – 3rd century – carrying 8 tons of raw glass.

[17] Trace element analysis of colourless glass showed these were made using sands from different sources, giving some support to the de-centralised production hypothesis.

Natron was no longer in use, and the low lime composition of the Bet'eliezer glass could suggest declining access to the material from at least the 6th century onwards.

[22] Detailed compositional data recently summarised by (Lankton, & Dussubieux 2006) has uncovered several distinct and yet contemporaneous glass technologies across the Indian Ocean, but the geographical assignment is not completely clear.

Previously analysed samples from the East coast of Africa and Madagascar could potentially fit this group, but further work is still needed.

Data from a site in South Africa, near the borders with Botswana and Zimbabwe, has tentatively assigned some beads to Islamic 8th century compositions.