Radiant Crystal

Radiant Crystal comes out of The Mineshaft, and it is a Gemstone, not a fish in any usual sense. The in-game line calls it an otherworldly glowing crystal that pulses with divine energy. The listing has no bait, weather or season, so there is nothing to prepare beyond reaching the zone.

Its numbers are small. It weighs 2 to 6.1 kg, averaging 2 kg, and sells at C$5 per kg, which gives an average value of just C$10. It grants 8 base XP. Among the 742 documented fish its average value ranks 728th, close to the very bottom, and its maximum weight is 528th of 663.

So the name promises more than the stats deliver. A glowing crystal sounds valuable, but it is one of the least valuable catches in the whole list. There is no limited or unobtainable tag, so you can catch it, only that it is rarely worth the cast.

My advice is not to treat it as a target. If it comes up while you fish The Mineshaft for something else, sell it for the few coins or keep it if you like a full collection. It will not pay for your next rod and will not move your level, so spend your attention on the zone's better catches.