White Gemstone

Condition

 Ever since "The Time Egg".

Resultant

 After obtaining this, Marle, Lucca, Ayla master the three tech "Poyozo Dance".

Difficulty
★★☆☆☆(Reliably available in the case of capture the Black Omen.)
Value
★★★★☆(Rare items can be obtained.)
Situation
from 65000000 B.C. to 1000 A.D. Black Omen

How to get

 Because there is "Mega Mutant" in the Black Omen, it is possible to obtain a "White Gemstone" if defeat it.