It’s debatable that if Truth Jewels are worth finding. The original usage of Truth Jewel is to merge into Truth Gem, which allows player to check the exact stamina and fatigue in game when carried in the rucksack.
In Story of Seasons: Friends of Mineral Town, players can actually check their stamina and fatigue through their top left screen, albeit not fully accurate. Which is also why most players really don’t see too much benefits in collecting them all. The reluctance is perhaps understandable, since one of the location is ‘almost’ in accessible unless the player is extremely dedicated… (ahem). Anyway, here are the locations:
- The water hole inside the horse stable
- The first lamp post south of Church
- The Goddess Statue at the left side of Church
- The bottom right bookcase located at 2nd Floor of the Library
- Purchase from Won with 50,000G
- Exchange coupon in Horse Racing (1000 coupon)
- Successfully answering 10 quiz in Town Villa during New Years period*
- The calendar in Mountain Cottage**
- Talking to Tomas while carrying 8 Truth Gem (to exchange all to Truth Gem)
Town Villa – This can be constructed with Gotz using 10,000,000G, with 999 Stone and 999 Lumber.
Mountain Cottage – Received as a gift during 50th wedding anniversary. I repeat, 50th. This is proven with a video from a China player, who decides to sleep 50 years (which took about 10 hours of pressing the bed continuously) to see the entire condition is true. For interested players, you may watch it here. The link may (or may not) work for US readers though.