http://www.potsaa.com/blue-bowl/

Is a bowl of blue glass, a symbol of the Grail? Or is it a silver cup?
I heard of a blue bowl kept at Glastonbury and wondered what the symbolism was.
Blue used to represent Christianity. The child Jesus and Mary ever used to be in this color sky blue in medieval painting. Well, I thought that the Grail was a cup of wood, but there are a thousand of these relics they went in quests, because for centuries only one male child in a family can marry if they had anything else to do.
Blue Bowl