hmmmm.
I had to look up aventurine but there are actually 2 types of gold coloured flecks in it.
One a flat solid that looks like gold leaf (going by pics I searched, a lot like aventurine) and a speckled gold that looks like aggregate.
I thought he looked quite old. He came from an estate auction.
I dont know much about murano so I will head the superior knowledge on this board

Thanks for having a look.