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.
Zlatno, Poltár District
Production of glass started in the village in 1833. Products had been transported to several world exhibitions. In the middle of 19th century came to Zlatno Leo Valentin Pantoček. He invented the way how to produce the glass money. Later this technique was named as hyaloplastics. In 1856 followed the invention of iris glass. A lot of production had been exported to United Kingdom and United States. 
In Zlatno had been a glasswork museum, which, however, ceased to exist. The glass factory stopped its production in 2003. However, several private companies continue in glass production.