The rock has green,purple and white stripes.
It looks as though it could be a specimen of blue john, an unusual mineral from which a large variety of ornaments are made. In England there is a famous mine in Derbyshire which has a factory for making ornaments and a shop which sells them to visitors. English blue john is said to be the finest. I'm not sure where your specimen came from. There are some yellowish tints in English blue john. which can be turned and polished on a lathe.