Hi ladies,
These pendants and other jewelry items have typically been made by companies in Murno such as Ferro & Lazzarini and many certainly date back to the 1980s and maybe earlier.
I believe that probably the majority of such items are made with millefoiri canes (murrine) from the Moretti company. But therein lies the start of a problem. Moretti canes have been sold to glass workers around the world.
In
this link showing a pendant in a box identical to Anne's mum's, a pleasing representation of a tree is given. I am reasonably sure it is genuine Murano and from the Ferro & Lazzarini company. Similar item shown in at least one of my paperweight books. Note the canes at the base of the tree.
However, a not-quite-as-good version of a millefiori tree has also been made in China (examples shown in a Chinese catalogue [Zibo] I have from the year 2000) and I would not be surprised to learn (as Sue has stated) that modern versions of such work are coming out of Taiwan.
Perhaps those items in boxes like Ane's are indeed Murano, but can we say whether Chinese or Taiwanese equivalents are sold in their own particular boxes?
As with general Murano gift wares, it would make life for collectors much simpler if items were marked with the original maker instead of just generic labels and box wording.