For Saxony 's economy , this dye was an important export item .
The blue dye made from the ore was used for colouring both glass and enamel , for ceramic glazing and later for painting porcelain .
For Saxony 's economy , this dye was an important dye   .
The blue dye made from the ore was used for colouring both glass and enamel , for ceramic glazing and later for painting porcelain .