Please increase crystal sand amounts

[seekified]

I have been in this stage of relic for over a month
mainly due to farming crystal sand, on the other hand, I could get like 5 times umbrites, since I have no use of Lore
since I stop gathering at lv50, and never done any crafting class over 25
many have suggest to farm amber, I m not sure does the leve level have any effect of the chance of the lockbox pop up
so far I have only try 6 lv52 leve and do not have any luck
should I go for level 58 leve instead?

Leve level doesn't matter. 100 leves will usually get you 10-20 chests, depending on how lucky you are with RNG. Trying 6 leves and giving up isn't nearly enough effort for this type of farming.

I recommend the leves "Dance Magic, Dance" or "Don't Come Back" since it's easy to spot the chests in their relatively small areas. If you do Don't Come Back, note that chests can also spawn underneath the yak that you're supposed to escort. Start the leve, look for chest, abandon leve, rechallenge leve, repeat.