I found this object , made of stone (agate, I think) silver mounted. It has no marks but I tested it.
It is not old, but it looks handmade with a good workmanship.
I do not know exactly where it comes from and what it's for, but I guess that is a Tibetan object to pour holy water.
I did not find pictures of a similar item on the internet.
Someone has some more information about it?