Heroic dungeon quest 250jade accessory reward

Hi what exactly is a reward from that quest? Is there anything special about that "bead"? It has the same description as regular bead that drops all the time from the moobs, just slightly different icon?
Screen for reference:

 

You get a relic piece 1-5 for the dungeon you are running, in this case 4k ck relic

 

Thats a reward for 50 of jade accessory not 250

 

You get one WT/SCM marble.

Not particularly.

No. It is the exact same marble drop you get from mobs in WT/SCM dungeons.

 

So the quest is basicaly do the dungeon 250+ times (and have ~1000 marbles in depo already) to get one more marble? ; wut

 

You do not have to do the heroic quest if you do not need more marbles.

 

Very useful quest for SRS marble though. SRS marble is rare drop and useful to craft the SRS ornament compare to SCM marlbe that only used to craft untradeable cloth, weapon & useless ornament.