Secret Gem

Hidden Ore (秘められし原石) is a material available in Kingdom Hearts Birth by Sleep. It can be used during Command Charge to raise the synthesized command to its max level.

Design
Hidden Ore is represented by four jewels with a unique structure. The main jewel is the largest, is tube-shaped, and has facet cuts. Two medium-sized jewels are hook-shaped and revolve around the main jewel. The smallest jewel floats between the two hook-shaped ones. All four jewels are golden yellow, and the largest one has a swirling, purple and yellow, smoky design in its center.

An ore is a type of rock that contains important minerals, such as metals. "Hidden" may reference the fact that the material can only be obtained by defeating Vanitas's Lingering Spirit, a boss that can only be encountered after certain circumstances have been met.

Kingdom Hearts Birth by Sleep

 * Hidden Ore: Vanitas's Lingering Spirit (100%)