The garlic is Asiatic Turban type.
All of my garlics of this type have similar purple striped skins. This type of garlic normally doesn’t have a long storage life, but this is my first year with this garlic so I don’t have any first hand experience. This one didn’t grow particularly well, but the bulbs are a reasonable size and they didn’t open up in the ground.
They are very pretty too. I quite like the purple stripes.