I've tried looking on the wiki, searching on YouTube, going to the exact coordinates and thoroughly searching the area but I can't find these silica pearls on Lost Island at Spirit Falls.
Caves - ARK: Survival Evolved Wiki Guide - IGN
Ark Survival Evolved - The Island - Artifact of the Brute Guide - YouTube
Lost Island - ARK: Survival Evolved Wiki
Ark Caves Guide: All Island Cave Locations And Rewards - eXputer.com
Far's Peak - ARK: Survival Evolved Wiki
Top 10] Ark Survival Best Base Locations And Why They're So Good | GAMERS DECIDE
All Artifact Locations in the Lost Island expansion for Ark: Survival Evolved - Gamepur