Blue Shiny Pebble is one of the pebbles needed for the Pebbled Plunder Accomplishment and can be found in the Flooded Fortress not too far from both main stairs that can be accessed from the east.
Fairy Bug : r/Palia
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Purple Shiny Pebble - Official Palia Wiki
What else can i do? : r/Palia
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Official Palia Wiki
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