Avventurina or Aventurine is the name given to the tiny metallic sparkles in Murano Glass and this has justifiably become one of the most popular of the Murano Glass making techniques.
Avventurina is a Murano glass-making technique developed on Murano island in the 17th century. It was first mentioned in a document dating from 1614 as "a kind of stone with gilt stars inside". A glass artisan is said to have accidentally dropped some metal shavings into the glass mixture as he was working it.
The recipe involves adding various metal oxides such as copper and iron to the hot glass mixture, which causes tiny particles of the metals to crystallize as the glass mixture cools off creating the unique sparkling swirling famous worldwide.