History of glass
Glass remained a luxury material, and the disasters that overtook Late Bronze Age civilizations seem to have brought glass-making to a halt. It picked up again in its former sites, Syria and Cyprus, in the 9th century BC, when the techniques for making colorless glass were discovered. The first glassmaking "manual" dates back to ca. 650 BC. Instructions on how to make glass are contained in cuneiform tablets discovered in the library of the Assyrian king Ashurbanipal. In Egypt glass-making did not revive until it was reintroduced in Ptolemaic Alexandria. Core-formed vessels and beads were still widely produced, but other techniques came to the fore with experimentation and technological advancements. During the Hellenistic period many new techniques of glass production were introduced and glass began to be used to make larger pieces, notably table wares. Techniques developed during this period include 'slumping' viscous (but not fully molten) glass over a mould in order to form a dish and 'millefiori' (meaning 'thousand flowers') technique, where canes of multicolored glass were sliced and the slices arranged together and fused in a mould to create a mosaic-like effect. It was also during this period that colorless or decolored glass began to be prized and methods for achieving this effect were investigated more fully.
Hellenistic glass
Hellenistic glass is the typical soda-lime-silica glass, to which lime was not intentionally added, but it was provided through the agent of sand. Although, it cannot be argued with certainty where the Hellenistic primary production of raw glass was geographically located from the archaeological record, we can hypothesize that a large part of glass production took place in the Syro-Palestinian coast or the broader Levant and Egypt . In favor of this argument are comments of classical writers of the period or a little later, like Strabo (63 BC) who mentioned the Belus river on the Syrian coast to have been used for glassmaking or even by writers other such as Pliny the Elder (23-79 AD) or Tacitus (c. 56-c. 117 AD). However, archaeological evidence firmly indicate that primary production of glass, as well as glassworking took place on the island of Rhodes in the Aegean, during the Hellenistic period and, particularly, after the foundation of the city of Rhodes in 408 BC, and even earlier through the Classical period.