| Glass was used as a material in
the Middle East at least since the 15th century BC. The earliest
evidence of glass production come from Egypt and Mesopotamia. But the
production of thin-walled glass vessels, using the blowing technique,
can be dated only to around 70 BC. That discovery was probably made
somewhere in Palestine. The Middle East was a centre for glass
production throughout the antiquity, even if the art of glass-making
also spread to Europe. This tradition continued all the way into the
Islamic period. The introduction of glass-blowing technique made glass
items cheaper to produce and as such glass vessels were no longer only
luxury items, but became more commonly used. This is also confirmed by
archaeological finds which indicate the increase of glass finds
beginning during the Early Empire (1st. century A.D.-3rd century A.D.)
and continuing into Late Antiquity. The raw material for glass production includes quartz sand, soda (sodium carbonate) and lime. Colour is obtained through different ways, e.g., by adding different metal oxides. Magnesium can be added to neutralize the natural colour in glass and to produce transparent, almost totally clear glass. Quartz requires about 1700º C to melt, but by adding soda the melting point can be lowered. The glass-melting furnaces in Antiquity could probably be heated to about 1050-1100º C. Glass heated to1080º C is fluid enough to be worked into shape by blowing. Similarly to metals, broken glass can be re-melted in order to produce new glass objects. Already in antiquity the collection of old glass material was practiced to provide raw material for the glass-blowers’ workshops. Especially in the Byzantine period, when some areas experienced economic depression and the acquisition of new raw material could be difficult, the recycling of old glass became important. This phenomenon is confirmed in the excavations of the Byzantine monastery at Jabal Haroun. Broken glass there was collected and stored for re-melting. Simultaneously, it seems that at least some of the glass objects recovered in the excavations appear to have been made out of recycled glass. Most of the glass found at Jabal Haroun is in a very fragmentary state, yet the items can be recognized according to their types. Pieces from different glass beakers and cups and from a couple of plates were found, as well as pieces from different types of storage vessels and bottles. About a quarter of all glass pieces found in the excavations at Jabal Haroun originates from different types of tableware, containers and transport vessels. A second quarter of the finds consists of window panes and some inlays. The window panes usually belong to the type of round, so-called bulls-eye windows, which were used in the Byzantine churches since around the 6th century. The third, most numerous group, a roughly half of all the found glass material, can be recognized as glass lamps. These are divided in two main groups: single, bowl-shaped lamps with three handles, which were suspended from metal chains, and cup-shaped lamps with a stem, of the so-called polycandelon type, which were hung in clusters using different types of chandeliers. Most of these glass objects had probably been produced in some local workshop in the Petra area. A specific small group of glass items are the vessels from the Early Islamic period, most probably imported items. To this group belong a couple of straight-walled vases made of turquoise-coloured glass, which are decorated with pinches in circles. Also pieces of a broad plate, probably on a foot, were found, decorated with geometrical incisions and a repeated single Arabic word. A group of its own are the mosaic cubes (tesserae) made of glass in different colours, which were used in church wall mosaics. No preserved fragment of a wall mosaic has been found at Jabal Haroun, but many hundreds of mosaic cubes recovered indicate that some wall mosaics, at least during certain occupation phases, decorated the walls of the church. |