Wrong quest letter

Apparently there is wrong quest letter
I found Queen bee letter and it said I must gather 30 gold dust.
So I use my craftman to collect gold dust outside the zaid.
But after 30, I delivered them to Pet trainer and she reject it.
Im frustated and later need more slot inventory so I drop that letter.

Then when I reach higher level and hunting on east red soil, I found a loot named "... gold" or whatever probably the right item.
But I swear the letter said it gold dust.
Can somebody clarify this ?

May we know what part of episode is that and the name of the quest? Maybe we can help you.

Uh, it's not main quest.
Just random letter quest dropped from Queen bee on Soil dimension.
Not really important but it easier to manage than quest from quest manager