Floating crystals can be fished with a net on Tarddiad. They give 120 Fishing experience per crystal fragment. Level 75 is needed to fish them.
Normally they can yield up to two crystal fragments. Wearing pieces of the crystal armour or the attuned crystal armour increases the maximum number of crystal fragments players can obtain per successful catch by one for each pieces worn, excluding the first armour piece. Players wanting to collect enough crystal fragments for a full set of attuned crystal armour should buy a full set of crystal armour in order to maximise the average amount of crystal fragments they can obtain.