For this mandala pattern you can use any yarn you like with a suitable hook. I have used 3 colours of Drops Muskat from Drops garnstudio with hook EU 4 mm (US G/6). I have also used fingering yarn like Rainbow Cotton 8/4 from Hobbii with hook EU 3 mm (US C/2).
The mandala measures 28 cm/11 inch with Drops Muskat and 24 cm/9,5 inch with Rainbow 8/4 before blocking.
Pictures of each round with instructions follows.