Help with stone identification required

[UKRob]

This stone was gifted to me by a member on a UK forum who got it as part of a package. It's quite small as you can see below and was pretty mucky before I lapped it - which was not too difficult on an Atoma and finished with wet & dry up to 1000. It slurries nicely with a pale purple colour although the stone itself is a much darker purple. The pictures are not great but I'm hoping there's enough to help identify what stone it is. In order they show wet, with slurry and dry.

Thanks in advance.