Hello all!
I was explaining a few things to some friends a week back and thought I should post that info here:
When you first start your gathering, be it fish/bot/mine the item you can harvest is chosen as soon as you pick the first setting, for Mining- Exposed Ore ( depth )
With this info and a look at your remainder bar you can tell what that item might be, the remainder bar in the photos relates the current item.
Common item: limonite, copper ore, ect.
Remainder bar starts near the H in "Approach"
Rare item: Gemstones, Mythril, ect.
Remainder bar starts near the middle of "Approach" two swings is about all you'll get
Leve Item: HQ Iron Ore, HQ Mythril, ect.
Remainder bar is past "Approach" leve items will always take two successful hits to dig so you have a chance to cancel.
The times I use this most is for avoiding those pesky leve items so I can keep mining mythril over and over while failing any time I see the HQmythril spawn.
Hope this helps!