Amazonite

Amazonite is the most valuable of all minerals in the game, with a value of $500,000 and 500,000 points. It is only found in the greatest hellish depths of Mars.

Due to its extreme value, it is crucial to collect to prepare for the Ending. A single piece of Amazonite can pay for a top-tier upgrade from Autobuy 2000. $500000 is also enough for either 66 Hull Repair Nanobots or 100 Plastic Explosives, both of which are critical for the Ending.

Trivia

 * In real life, amazonite is an obscure mineral with an opaque blue-green colour that is not particularly valuable, while in-game they look like little stars and sparkles. It is likely that the developers made up the name for a fictional ultimate mineral and are unaware the name is held by a real mineral.