Quartz

Quartz is the 8th clue. It is a Tomas clue and was located in Marianas Trench.

History
Not much is known about how this clue was put in the bottom of Marianas Trench. However, since the Tomas are extremely athletic and adventurous, they wanted to put the clue in a place where it would be extremely hard to reach. They also trained seals to wear cameras and to guard the clue.

Quartz
Quartz is an opaque semi-precious mineral. The chemical formula for Quartz is SiO2.