Pukhraj stone when extracted from mines comes in various qualities. There are low qualities Pukhraj Stones and high quality Pukhraj stones.
The difference in quality in indicated by the inclusions and shine of the Pukhraj Stones. Low quality Pukhraj stones have a lot of inclusions in them and are of dull with lifeless colour.
But Astrologers and Pundits recommend to their clients that "Wear a Peela Pukhraj with minimum inclusions in it". This kind of Pukhraj Stone comes at a very high price and everyone can not afford it, so a process of treatment in which either glass, beryllium or other external materials are filled in the Pukhraj Stone started.
By this process the inclusions in the Pukhraj Stone gets less visible and the colour and luster improves. This makes the Pukhraj Stone look better to look at and its perseved value is increases.