Notice on them pants Spirit Crystal as Raw Material? You won't be able to collect those, rather you have to salvage uncommon or rare gear in order to obtain. Any lvl 20 or below item that is salvaged yields Spirit crystal as a common item and mysterious essence as the uncommon drop. When crafting rare pants, chest and helm, be prepared to make uncommon gear just to salvage 'em!
Your sprite's salvage lvl must be equal to item lvl for this to work and the process is a bit costly.
Saphael's energy or essence item, also required for crafting, drop from bosses as rare drops or completing a chain quest series. They are rare so you may need to buy them from other players.
Condemned Mine drops essence saphael, Prairie Cave drops energy Saphael. You may also get them from quest, as rewards.