Path For Odd Shard Hunting:
Very common:
Red Shard
Blue Shard
Yellow Shard
Green Shard
Common:
Hard Stone
Revive
Star Piece
Comet Shard (UltraSun & UltraMoon only)
Path Brilliant Stone Hunting
Very common
Hard Stone
Everstone
Float Stone
Common
Fire Stone
Thunder Stone
Water Stone
Leaf Stone
Ice Stone
Sun Stone
Moon Stone
Oval Stone
Rare
Shiny Stone
Dusk Stone
Dawn Stone
Light Clay
Path For Rare Teasure Hunting
Very common
Hard Stone
Pearl
Common
Big Pearl
Nugget
Rare Bone
Pearl String
Big Nugget
Comet Shard
Very rare
Gold Bottle Cap
Cover Fossil (UltraSun & UltraMoon)
Skull Fossil (UltraSun & UltraMoon)
Helix Fossil (UltraSun & UltraMoon)
Claw Fossil (UltraSun & UltraMoon)
Jaw Fossil (UltraSun & UltraMoon)
Armor Fossil (UltraSun & UltraMoon)
Plume Fossil (UltraSun & UltraMoon)
Dome Fossil (UltraSun & UltraMoon)
Root Fossil (UltraSun & UltraMoon)
Sail Fossil (UltraSun & UltraMoon)
Interesting Item Hunting
Pokémon could find any item from all the accessable paths.
But with two exceptions, one being the Hard Stones. Hard Stones are
"Very common". And in UltraSun & UltraMoon, Comet Shards cannot be found in the second isle development stage, while in the third stage they are "rare".
Source
Sorry, but I couldn't find the exact percentages, but I hope this is fine too.
That's all!
SeeYaLater!
[IMPORTANT EDIT IMO]: I saw on a Bulbapedia page (Coba Berry) Mentioning something about it being rare and then doing '(5% chance)'. So I guess that's a bit that?