Question

Some of the glass objects recovered from ancient monuments look milky instead of being

transparent. Why?

Answer 1

As glass is supercooled let liquid ,so it has tendency to flow though very very slow.
So if we see ancient glasses,they look thicker from bottom as glass flowed down and look less transparent and more milky

Answer 2

Hey !!

When amorphous solid (glass) are heated and cooled slowly, they acquire crystallinity at same temperature. Glass objects of ancient monuments, over a period of years, are exposed to sunlight and cooled during night times, which has resulted in the crystallization of the glass object which imparts milky colour to the ancient monuments.

Good luck !!