The colorless and crystal-clear glassware was first made in Iran during the Achaemenid dynasty (550 BC - 334 BC), archeological surveys on several hundred found glasswares show.

“It was during the Achaemenids that the glass blowers were for the first time introduced to colorless glass blowing techniques, an important stage in the glass blowing process,” Arman Shishegar, an expert on ancient industries and glass blowing techniques, told CHN.

The technique was imported from Syria, Iraq and Turkey, all part of Achaemenid Empire at the time, Shishegar says.

“Silicates, Copper and Iron oxides all make the glass stained and blurred. But, by using magnesium, Achaemenid engineers succeeded to made the glass clear and colorless,” said Shishegar.

Many ancient text have also described these colorless and crystal-clear glasswares, which were once used as decorative items at the Achaemenid court. Aristophanes, the Athenian playwright, also mentioned these crystal-clear glasswares when describing the Achaemenid court in his play, Acharnians.

Nowadays, glass manufacturer use zinc oxide instead of magnesium oxide for producing crystal-clear glasswares.