Tektite

Description from game: "One of the most valuable and rare meteors discovered in the martian quarry. More can be found in the granite layer and below."

Tektite is considered one of the best ores in the game mid-game due to its high value and commonality relative to its high price. Tektite gives off a dark red glow which makes it easier to find while in the depths of the quarry. As the description states, tektite becomes slightly more common as you get deeper below depth -600.