Avventurina

Glass of a yellow - brownish colour, translucent, in which copper metal microcrystal are dispersed to reflect a gold colour, formed by deglassification (separation from the molten mass during the cooling step). It is prepared by melting the mixture of transparent colourless glass with the addition of cuprous oxide and iron and lead oxides. Melting takes place in a reducing chamber and the molten mass should be cooled very very slowly. Traditionally, to obtain the best quality, once the mass is molten, the oven is switched off and left to cool on its own for several days. Once room temperature is reached, the crucible is smashed and the avventurina is found under a layer of coloured oxidized glass.
This glass found its highest application in Murano in the mid-nineteenth century, first at the furnaces of Pietro Bigaglia and then at Salviati & Co., where it was melted once again and blown to obtain extremely rich and elegant items, often made for the royal families of the day. In the twentieth century avventurina was used by only a small number of glass - works as it was very difficult to obtain. Special mention should be made here by Barovier & Toso's and Aureliano Toso's who, on designs by he painter Dino Martens, executed a series of vases with this material decorated with applied multicoloured strips.